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This chapter was devoted to some of the most common, ecologically and economically important, interesting, and indicative plant species of the vast and remarkably diverse mixed prairie. Species presented in this chapter did not necessarily include the dominants or associates of the various range types within the mixed prairie because those defining species were frequently presented with the specific range types--the titled and numbered Society for Range Management (Shiflet, 1994) rangeland cover types and other published mixed prairie communities which comprised the subject matter of chapters, Mixed Prairie I and Mixed Prairie II. Likewise, some mixed prairie plants were presented in both this chapter and, also, in one or the other chapters of Mixed Prairie I or Mixed Prairie II.
Apologies were hereby given for any frustration this arrangement caused viewers, but it was probably less confusing and easier to locate plant species with this arrangement than with the alternative arrangements of including either 1) all plants in the large chapters devoted to range types of the mixed prairie (and swelling these chapters to even larger size) or 2) all plants in the chapter devoted to plant species of the mixed prairies (and compelling students to navigate back and forth among chapters for each range type and its dominant species).
Confusion and awkwardness was unavoidable when covering the often confusing mixed prairie and its admittedly ambiguous boundaries and its ecotones with adjoining range plant communities. The distinction between mixed prairie and shortgrass prairie or semidesert grassland was as indefinite as the transition zones themselves. In this context, some plant species that grow in mixed prairie yet are more characteristic of nieghboring range types were presented in those chapters (eg. Shortgrass Plains, Semidesert Grassland, True Prairie).
Treatment of these range types was not conducive to convenience.
test 1. Mature sand dropseed (Sporobolus cryptandrus)- Appearance of adult sand dropseed plants complete with the cryptic infloresences still enclosed within the boot. West Texas Cross Timbers. Erath County; Texas. Late August.
2. Sand dropseed (Sporobolus cryptandrus)- This mid-grass is one of the most widely distributed grasses in North America. The biological range of this species is literally from Atlantic to Pacific and from northeastern North America into the deserts of the Southwest. It is generally an increaser that is most common on grasslands in various mid-sere communities, but sand dropseed is a climax or at least higher seral stage species on certain range sites of mixed prairie, Palouse Prairie, and semidesert grasslands (Dodd, in Gould, 1968, ps. 331, 334, 336). As suggested by the common name of sand dropseed the most favorable edaphic habitat for this widespread grass is that containing higher proportions of sand (or, sometimes, gravel).
Sand dropseed is not as palatable as some of the grasses with which it is associated but it does furnish moderate to high quantities of forage that is of good down to fair nutritive value with increasing stages of maturity. (The individual shown here was past seed-shatter stage and approaching the dormant stage when forage value is lowest.). Although sand dropseed is a bunchgrass it does have fair to good sand-binding potential due to it's preference for coarse-textured soils.This common range grass was one of the 200 range plants on the Master List of the International Range Plant Identification Contest sponsored by the Society for Range Management.
Taylor County, Texas. October.
3. Sand dropseed at peak bloom- This plant had been mowed frequently during the summer growing season on Texas' Rolling Red Plains such that it was stunted and blooming at end of autumn (less than a month before first frost). The entire aboveground portions of this cespitose species were obvious in this depauperate individual. (Runt specimens formed by stresses such as over-utilization frequently make some of the best examples for overall or composite shots of a plant because their short stature provides greater depth-of-field.)
Soil chroma shown here was representative of soils on the Rolling Red Plains, Rolling Redlands, or simply Redhills section of the Great Plains physiographic province that extends fromn Texas to southcentral and southwest Kansas. The smaller (and mowed) bunchgrass in the right background was Texas wintergrass which is commonly co-dominant with sand dropseed on deteriorated mixed prairie ranges throughout this general area.
Taylor County, Texas. October.
4. Panicles of sand dropseed- These inflorescences of S. cryptandrus exhibited the two basic forms or patterns of this species: 1) fully exerted pyramidal-shaped and 2) partially or entirely included (= enclosed) within the sheath (ie. still largely inside the boot). The latter is basis of the specific epithet, cryptandrus, meaning crypt-like or hidden as in a crypt.
Taylor County, Texas. October (flowering delayed by repeated defoliation).
5. Stand of maturing sand dropseed- Local population of sand dropseed nearing senescence and dormancy in mid-autumn in the West Cross Timbers of northcentral Texas. Besides nearing end of their annual growing cycle these perennial plants were suffering from the stress of moderate to severe drought. Furthermore, plants of sand dropseed that are growing in sand typically reach larger size (height, number of tillers, area covered) and exhibit more vigor than those growing on 'tighter" soil.
Erath County, Texas. October; grain-shatter stage.
6. Just to make sure there's enough- Three examples of panicles in sand dropseed. Sand dropseed is one of the most widely distributed grasses in the mixed prairie and adjoining range types. It is often stated among Texas rangemen that there are probably more plants of sand dropseed than of any other grass species in the state. Given such commonness and widespread distribution, plenty of examples of sand dropseed were included herein. Incidentally, sand dropseed is one of the more difficult species of grass to present photographically to good advantage (and of course few, if any of the Gramineae are photogenic to the degree of the more colorful forbs).
Identifying details of the sand dropseed inflorescence were presented in the next set of slides and their caption.
Erath County, Texas. October; grain-shatter stage.
7. Hidden up close- Two views of the incompletely expressed or extended panicle of sand dropseed. In this species the mature panicle typically remains partially to almost completed enveloped within the sheath rather than becoming emergent (ie. the inflorescence stays in the boot even upon maturity) This results in panicle branches remaining pressed (appresed) against against the central axis of the inflorescence and the sheath having a "swollen" appearance. The specific epithet cryptandrus means "with hidden flowers". Thus the scientific name of this species is based on the morphological feature of an incompletely exposed or extended inflorescence.
Diggs et al. (1999, p. 1327) cited work that reported the tiny grains of this species being eaten by American Indians. As if dietary use of Indian ricegrass (Oryzopsis hymenoides) was not "hard scrample" enough.
Erath County, Texas. October; grain-shatter stage.
7a. A key characateristic- Rings of straight, relatively long, white pubescence surrounding the collar on a shoot of sand dropseed. This morphological trait and retention of portions of the lower panicle within the sheath (boot) have long been regarded as the key identifying features of sand dropseed, especially in the field. Hatch and Pluhar (1993, p.109) stated that "the most distinguishing feature of this grass are [sic] the long dense hairs at the collar".
Erath County, Texas. October; grain-shatter stage.
8. Green alkali- An extremely robust individual of alkali sacaton (Sporobolus aeroides) growing on a very favorable microsite in an area that had been usually blessed with rains provided a good example of the size and vigor of which this species is capable. This specimen was growing on a classic mixed prairie with big bluestem (Andropogon gerardii), silver bluestem (A. saccharoides), sideoats grama (Bouteloua curtipendula), blue grama (B. gracilis), and buffalograss (Buchloe dactyloides) as well as various forbs. (Plants of all the species just listed were growing within ten foot of this featured plant).
Alkali sacaton was included on the Master Plant List of 200 species for the International Range Plant Ideitification Contest sponsored by the Society for Range Management (Stubbendieck et al., 1992, ps 136-137). Another good discussion of alkali sacaton from the range plant point of view was the Range Plant Handbook (Forest Service, 1940, p. G109).
Location note: other examples of alkali sacaton were included within Range Types of North America as in the chapter, Mixed Prairie- IA, Southern and Central Great Plains. This example was placed after sand dropseed in this chapter to give an example of another Sporobolus species important on Great Plains.ranges.
Quay County, New Mexico. Mid-July; grain at mid-maturity stage.
9. Needle-and-Thread- A cespitose bunchgrass of mid height (ie. midgrass). Stipa is one of the more widely distributed Gramineae genera whose species are dominants across a number of North American grassland range types extending from the continental true and mixed prairies to Pacific coastal and California bunchgrass prairies. Moffat County, Colorado, June.
Note on location: Needle-and-thread (Stipa comata), New Mexico feathergrass (S. neomexicana), and green needlegrass (S. virida) were covered previously in this chapter (above).
The grama grasses (or usually called gramas in range parlance) arguably constitue the single most important group of grasses of the mixed prairie and, perhaps, the shortgrass plains as well as for example the blue grama-buffalograss or sideoats grama-silver bluestem range types. This is expecially true for the Southern and Central Great (High) Plains. Hitchcock and Chase (1950) made much use of a taxonomic level they called Section as the main subdivision of various Gramineae genera much like the subgenus taxon used by other authors as for example to divide species within Quercus and Opuntia. In this format Hitchcock and Chase (1950, ps. 532-533) subdivided Bouteloua into the Atheropogon (Section 1) with "spikelets not pectinately arranged" and shed as a unit (florets and glumes falling together) and Chondrosium (Section 2) with "spikelets pectinately arranged" and having mature florets shed from persistent glumes. Thus B. curtipendula, B. rigidiseta, and B. aristidoides were in Atheropogon while B. gracilis, B. hirsuta, and B. trifida werre in Chondrosium.
Half a century later (Shaw (2008, ps. 86, 88, 96-103) elevated Chondrosium to genus-level and retained Bouteloua only for members of Atheropogon section. Thus, for Colorado (the political unit covered by Shaw [2008]) blue grama became Chondrosium gracile with the sole Bouteloua species left in the Centennial State being B. curtipendula, sideoats grama. Barkworth et al. (2003, ps.250-252), the encyclopedia for North American grasses (north of Mexico), did not split the historic Bouteloua but instead used the sections of Hitchcock and Chase (1950, 532-533) as subgenera. Bouteloua species in Bouteloua subgenus were those with flower clusters terminating in entire, bifurcate, or trifurcate tips and with disarticulation at base of branches whereas Bouteloua species in Chondrosum subgenus had inflorescences terminating in a point or spikelet and with disarticulation above glumes.
Binominals used herein also followed the historic, standard treatment of Bouteloua as a single genus. Distinctions among Bouteloua species according to the two sections first shown in Hitchcock and Chase (1950, ps. 532-533) and, now, subgenera in Barkworth et al. (2003, ps. 250-252) appeared to the present author to be self-evident as was retention of traditional nomemclature.
10. Sideoats grama (Bouteloua curtipendula)- The State Grass of Texas is the textbook example of a midgrass species. It is the dominant grass over much of the Mixed Prairie and is often co-dominant at larger spatial scales (regions) with other midgrasses like western wheatgrass. Central and western portions of the Mixed Prairie support a higher cover of midgrass than of tallgrass species and some of the more mesic sites of the western zone of Mixed Prairie have a greater proportion of midgrass than of shortgrass species. As such, Mixed Prairie is sometimes known also as Midgrass Prairie even though some species of the three general grass groups are common. Sideoats grama includes both rhizomatous (B. curtipendula var. curtipendula) and non-rhizomatous or bunchgrass (B. curtipendula var. caespitosa) forms. These two varieties are sometimes co-existent as on ranges in the Cross Timbers, Edwards Plateau, Rio Grande Plains, and Trans Pecos Basin and Range Regions of Texas. While the specimen seen here appears to have the bunchgrass or cespitose growth form it is actually the rhizomatous variety which is growing in isolated strips or patches of soil between slabs of limestone which is the parent material of the Grand Prairie supporting this lovely grass. (Rhizomes of sideoats grama were shown at end of this species treatment.)
Like other Bouteloua species and such short grasses as buffalograss, and curly mesquite sideoats grama "cures on the vine"(ie. the dormant, dried leaves and even stems retain a fairly high proportion of the nutritive value of the growing plant). This phenomenon, which is due to a combination of several factors such as the nature of eragrostoid vs. panicoid grasses and dry winters in which nutrients are less leached from herbage, was described as "self-curing" and was seen as the basis of "winter grazing" on the Great Plains. This was recorded in the prescient report by Dr. Hiram Latham (1871): Trans-Missouri Stock Raising. The Pasture Lands of North America: Winter Grazing. This is one of the rarest of all materials dealing with the Western Range. It was re-published by The Old West Publishing Company in Denver, Colorado with an introduction by J.C. Dykes (1962). Well worth the effort to borrow or buy and read this seminal view of early North American ranching. It is just another example of the rich recorded history of Range Management.
This is an example of a range microsite. It is a Brackett soil that is too small for a mapping unit in the soil survey. The Brackett is situated between the general Purves Dugout soil association. This narrow strip of Brackett is a "postage stamp-size" of the Limestone Hills range site within the larger, surrounding Rolling Prairie range site. The limestone outcroppings spread water to the intervening Brackett soil to create a mesic microhabitat. On both of these range sites sideoats grama is an increaser while the predominant decreasers are Indiangrass and little bluestem.
Even in a "rockpile" on plate-thin soil and four years into the worst drought in a half-century this prairie beauty is blooming profusely to assure the perpetuation of its genetic heritage. Erath County, Texas. October.
11. Given its importance- Along with being one of the classic example species of a midgrass, sideoats grama deserves special recognition (and extra coverage) for various other "virtues" (reasons, features, examples, etc.) including that it is: 1) the climax co-dominant, along with silver bluestem (Andropogon saccharoides), over much of the Rolling Red Plains/Rolling Redlands complex in the Southern Great Plains or the Mixed Prairie Climax of Weaver and Albertson (1956, ps. 266-274 passim); 2) one of the most widely distributed climax grasses throughout most of the vast Great Plains Province;3) an extremely palatable and major forage-producing midgrass; 4) one of the most drought-tolerant of all native midgrasses (Weaver, 1954, p. 235); and 5) a widespread grass in both true and tallgrass prairies varying in disturbance response from decreaser through increaser (most generally) to invader depending on range site (Clements, 1920; p. 132; Weaver, 1954, ps. 55-56, 282).
Gven these phenomena it seeemed unusual that sideoats grama (Bouteloua racemosa) was listed by Clements (1920; ps. 132, 133, 134) as forming consociations in only the tallgrass ("subclimax") prairie and the Desert Plains, known currently as the semidesert grassland, (Clements, 1920, ps. 144, 145, 146, 147) of the major grassland types (associations). Notwithstanding the fact that sideoats grama is not a dominant over as large as acerage as some other dominants, it is a major range grass throughout much of North America. Furthermore, the species range of sideoats grama extends throughout Mesoamerica and through South America south to Peru (Gould, 1975, p. 339). Sideoats grama has one of the largest, natural (not expanded by human action) biological ranges of any grass on Earth.
Sideoats grama is well-suited for range reseeding projects and is even commonly used for landscaping with native plants. There are at least varieties/accessions of sideoats grama in the United States with releases from Texas, New Mexico, Kansas, Nebraska, and North Dakota (Alderson and Sharp, 1995, ps. 20-23).
The plants presented as example specimens in these two slides were the cespitose or bunchgrass (non-rhizomatous) taxonomic variety, B. curtipendula var. caespitosa (versus B. curtipendula var. curtipendula as shown immediately above).
Caution: in the much of earliest ecological, including range, literature in North America, as for esample Clements (1920), sideoats grama was listed as Bouteloua racemosa rather than B. curtipendula.
Erath County, Texas. Early October; phenological stages ranging from anthesis to grain-ripe.
12. "Nothin' purtier"- There is nothing more pleasing to eyes of growers than reproducing organisms. These plants of cespitose sideoats grama were in process of producing a "bumper crop" of grain (spikelets). After an almost unbearable late apring through late summer drought that was rated as exceptional, recent soil-soaking rains were used by these plants to "go all out" for sexual reproduction. Note also, however, the plentiful tillers produced by these bunchgrasses. It was obvious that these plants did not omit asexual reproduction either. In fact, given that so many of these tillers (asexual propagules or clones of the genetic individual) developed inflorescences (that is, became sexual shoots) it was axiomatic that asexual reproduction was prerequisite for sexual regeneration.
The capacity of native range plants to exploit quickly and effectively opportunistically favorable ecological conditions and resources was portrayed graphically in these two photographs. Range grasses will survive if given a "fightin' chance". In the context of Charles Darwin's "survival of the fittest", species like sideoats grama survived because they reproduced (sexually and asexually). Only those species and individual organisms within species that leave progeny--that pass on their genes--survive.
Erath County, Texas. Early September; grain-ripe was the predominant stage of phenology although there was still anthesis in a number of racemes.
13. Inflorescence of sideoats grama- This raceme with its spikelets aligned along one side of the rachis illustrates the basis for the well-known common name of this eragrostoid grass. Close observation will reveal that spikelets originate on both sides of the rachis but those originating on the bare or naked side twist such that all (at least, most) spikelets point or extend off only one side.
Hitchcock and Chase (1950, p. 532) divided the Bouteloua genus into two sections:1) Atheropogon, those with spikelets not arranged pectinately (like teeth on a comb) and 2) Chondrosium, those with spikelets arranged pectinately. Most subsequent agrostologists followed this distinction as, for instance (Gould, 1975, ps.335) who changed Atheropogon to Bouteloua. In genus Bouteloua the sexual shoot culminates in a raceme or racemose inflorescence that has a central or main axis that is designated as a rachis. Arising or branching off of the rachis are two rows of units (or groups) of sessile spikelets. In section Atheropogon (or Bouteloua section) there can be twenty up to fifty of these branches that bear the spikelet units, each unit of which typically bears two to eight spikelets. In turn, each spikelet bears one fertile (perfect) floret and one to three sterile (often staminate) florets. These babies are loaded with viable seed.
Erath County, Texas. October.
14. One with mature spikelets- Compelling view of a raceme filled with fertile, ripe spikelets of sideoats grama against a backdrop of countless other fruit-laden racemes. This was a single grain-filled inflorescence among a "zillion" such racemes (= racemose inflorescence) that were produced following late summer rains that broke an exceptional drought. The reproductive ability--both sexual and asexual in this instance--of native grasses that evolved through natural selection was the key feature for species survival under harsh habitats, one of the most deadly and determinative features of which is drought. In southern North America, especially in the southcentral and southwestern regions, droughts can be particularily devastating. Droughts are arguably the greatest sources of plant stress and agents of denudation over much of the Western Range, particularly in the subhumid and semiarid southern plains. Drought remains omnipotent in deciding which range plant species persist and which do not.
When the good times (moist soil conditions during the plant-growing season) return, drought-adapted species reproduce quickly and prolificantly. Sexual reproduction was featured in this series of slides to give students an idea as to rapidly and abundance of plant propagules (germinules) production by genetic "reshuffling of the hereditary deck". Asexual reproduction was also apparent from the immense numbers of tillers that were produced by these sideoats grama plants (see again slides of cespitose individuals presented above).
Erath County, Texas. Early September; phenological stage in the featured raceme was grain-ripe just prior to grain-shatter stage.
15. Beauty of Texas' state grass- Raceme (= racemose infloresence) of sideoats grama at peak anthesis. The State Grass of the Lone Star State is not only one of the most widely distributed and most representative grasses across an array of range types, it is also extremely attractive especially when in flower. With bright red anthers highlight the tufted habit of this mid-grass it is at its showiest. Sideoats grama is a very attractive plant yet one discrete enough that it is more appreciated by those who care for finner things than by the uniformed and vulgar who can see beauty only in a rose bloom the size of a teacup.
Details of sideoats grama spikelets and their attachment was shown and explained in greater detail in subsequent slide/caption sets.
Erath County, Texas. Mid-October, peak-bloom stage.
16. Closer looks at beauty on a raceme- Spikelets of sideoats grama with both stamens and stigmas exerted, sometimes in the same spikelet. In sideoats grama there are units of (typically) two or three up to seven or eight spikelets attached on short, pendant (drooping) branches or "beanchlets" with each spikelet usually bearing one fertile floret and one to three sterile (often staminate) florets. In other words, each drooping branch can produce up to, say, eight fertile caryopses (fruits) and there can be as many as thirty or forty (or more) of these pendant branches per shoot or rachis (per raceme= racemose inflorescence). (See again from above slides examples of these sexual shoots or racemes.)
Erath County, Texas. Early September; anthesis.
17. Beauty in detail(s)- Floral units of sideoats grama at anthesis (pollination). Units of spikelets on pendant (drooping) branches off of the rachis of sideoats grama. Both stamens and stigmas were exerted in spikelets shown here. Note the rich orange to burgundy pigmentation of the anthers. There is usually one fertile (perfect) floret and one to three infertile (staminate or neuter) florets per spikelet in sideoats grama.
Erath County, Texas. Early September (first slide) and Early October (second slide); anthesis.
Footnote on photography: It was (is) "pert-nar" impossible to capture details of spikelets of sideoats grama on the land using slow film (Fujichrome Provia 100F, in this instance) and macrolense without artificial light because it was (is) necessary to use slow shutter speeds (1/15 to 1/60 second), in order to get adequate depth of field, under ever-breezy conditions. This situation was "true in spades" when trying to get flowering florets. Such a combination of variables was (almost always is) unavoidable when taking photographs on the range using only natural light. Under such conditions there are typically (again, almost always are) some spikelets that were wind-blown. A de-facto ecological lesson was that of anemochory or aerochory, dispersal of plant propagules, germules, or disseminules (including pollen grains) by wind.
18. Just below the surface-Sideoats grama rhizomes with four (yes, count them) rhizomes shown in the first slide and parts of the four rhizomes shown in the second slide. It was explained above that there are two taxonomic varieties (some might make the case for two subspecies) of sideoats grama: the rhizomatous B. curtipendula var. curtipendula and the non-rhizomatous or strictly cespitose (or bunchgrass form) B. curtipendula var. caespitosa.
Mills County, Texas. October.
19. Texas grama (Bouteloua rigidiseta)- Hitchcock and Chase (1951) divided Bouteloua into two sections: 1) those with spikelets arranged in a pectinate (like the teeth of a comb) pattern and 2) those with spikelets not arranged in a pectinate pattern. Texas and sideoats grama are in 2) or not pectinate. Unfortunately this taxonomic relatedness did not result in Texas grama sharing the forage value or ecological status of it's section mate. Texas grama is not only a species of low forage value (due primarily to low productivity), but it is also invariably an ecological invader and indicative of disturbances like overgrazing. The generally low palatability and small size of this grass coupled with high rates of reproduction allow this invader to survive abuse and persist on depleted ranges.
Texas grama is an indictor plant, a species either: 1) indicating presence of certain environmental conditions, seral stages, or previous management and/or 2) chosen to indicate a certain degree of grazing use (Kothmann, 1974). In theory, all species are indicators of some environmental factor or condition. The concept of plants as ecological indicators was the basis of the second epic ecological monograph, Plant Indicators, by F.E Clements (1920) which was the sister volume and the more practical companion to his earlier and more famous Plant Succession (Clements, 1916). It was from the concepts explained in Plant Indicators that students in the plant ecology school of thought centered at the University of Nebraska developed many key applications such as use of quantitative ecology to determine range condition and trend based on climax or potential natural vegetation and the categories of decreaser, increaser, and invader.
20. A needlesome grama- Needle grama (B. aristidoides) is one of three annual Bouteloua species that calls semidesert grasslands and Chihuhuan Desert its home (Gould, 1975, ps. 341, 344, 346). And yes indeed, it does closely resenble threeawn (Aristida) species. Needle grama occurs in disturbed and otherwise marginal environments from the Rio Grande Plains up through the Edwards Plateau throughout the Trans Pecos Basin and Range vegetational areas (Gould, 1975, p.341 ). The current author photographed this specimen on a local denuded spot on silver bluestem-sideoats grama mixed prairie in the High Plains vegetational area of Texas where it, the Rolling Plains, and northwestern edge of Edwards Plateau converge (Gould, 1963; Correll and Johnston, 1979, map 1).
Forage value of this like the other annual gramas varies from fair when immature to poor at maturity as seen in these photographs. Like Texas grama treated immediately above needle grama is an invader and, most likely, of even lower successional status it being an annual.
Howard County, Texas. Mid-October; grain-ripe stage and nearing end of plant life.
21. Hairy grama (Bouteloua hirsuta)- This species is representative of those members of Bouteloua which have their spikelets arranged in a pectinate (comblike) pattern. Hairy grama is similar to Texas grama as it is usually an invader or on more harsh sites an increaser. Hairy grama is usually also more apt to be an associate or even a dominant species. Hairy grama is one Dr. Latham's "self-curing" species mentioned above, however its forage value, including palatability, is regarded as lower than that of neighboring species like blue grama, buffalograss, and curly mesquite. Hairy grama is less widely distributed, especially in the northern Great Plains than sideoats and blue grama. Erath County, Texas. October.
22. Racemes of hairy grama- This is an example of the pectinate form of racemes in Bouteloua species. Erath County, Texas. October.
23. Tall grama (Boutelous pectinata) in full-flower- This species is distinguished from hairy grama by its taller, more robust size.This specimen (along with the hairy and sideoats grama examples shown in this section) grew on a part of the Grand Prairie of Texas (tallgrass prairie). These species are widely distributed over the mixed prairie so were included in this section Hunewell Ranch, Tarleton State University, Erath County, Texas. September.
24. Tall grama racemes at peak anthesis- The inflorescence of Bouteloua species (especially those of the Chondrosium section) can be viewed as a raceme (s) composed or consisting of spicate branches on which sessile spikelets are borne in two rows on the rachis. The overall inflorescence type could also be interpreted as a panicle of spicate primary unilateral branches (Hignight et al., 1988, p. 7). Hunewell Ranch, Tarleton State University, Erath County, Texas. September.
25. Blue grama- Bouteloua gracilis is viewed by many range scientists as the single most important range plant in North America from the standpoint of its wide geographic distribution, dominance of total land area, impact on range ecosystems within its range, and forage contribution to range animal diets. Quite likely the only other range plant to offer any opposition to this distinction would be little bluestem, depending on whether certain taxa are interpreted as separate species or varieties of little bluestem. Of course any of the tallgrass species have the deck stacked against them now that so much of the land in their former species ranges was claimed by the plow. That matter clarified, students should remember that this is a widely distributed species (from the Atlanic states and provinces to the southwestern deserts and the western side of the Rocky Mountains). Blue grama occurs on some sites of every major grassland except the Pacific bunchgrass prairie. While the Great Plains is the center of it's range blue grama is locally common even in the shade of tallgrass species as in this example where it grew on a big bluestem- dominated prairie in the Dissected Till Plains of the Central Lowlands. The Central Lowlands is the general physiographic province of the Prairie Plains region and it's grassland vegetation.
Homestead National Monument, Gage County, Nebraska. August.
26. "King Grass of the Mixed Prairie"- Blue grama is the unquestionable overall dominant and the single most important range plant species of the mixed (and perhaps of the shortgrass) prairie. This is so in particular for the unit of potential natural vegetation designated as "Grama-Buffalo Grass" (K-65 in Kuchler, 1964; K-58 in Kuchler, 1966) extending from the Southern High Plains of Texas, Oklahoma, New Mexico, Kansas, and Colorado through to the Central High Plains of northeastern Colordo and southeastern Wyoming. This is probably the single largest unit of climax grassland vegetation in the Great Plains province. It would be rivaled only by the "Grama-Needlegrass-Wheatgrass" unit to its north (K-64 in Kuchler, 1964; K-57 in Kuchler, 1966). another climax grassland community in which blue grama is a dominant.
It would be difficult indeed to exaggerate the extent, economic and ecological importance, and role of blue grama in North American grasslands, and the drama of human occupation of this vast region. The noble Indian tribes of the Great Plains with their existence intricately tied to the buffalo depended on blue grama, a mainstay of the buffalo ranges, for their 10,000 to 12,000 years of occupation.
Blue grama frequently (perhaps even typically) grows in association with other range plant species, but it also forms natural and extensive single-species stands. These almost exclusive populations of blue grama or range plant communities in which blue grama is the sole dominant constitute what Clements termed a consociation. In the classic Grassland of the Great Plains Weaver and Albertson (1956, 149-150, 253-254) described co-dominance and close affilitation of blue grama and buffalograss. When blue grama is co-dominant with buffalograss it is--contrary to popular opinion and perception--blue grama that is the more drought-tolerant species (Weaver and Albertson, 1956, ps 33, 104). Clearly, "... buffalo grass is less drought resistant than blue grama" and, also, "[B]lue grama is much more drought resistant than buffalo grass... (Weaver and Albertson, 1956, p.79, 133, respective quotes). The stoloniferous buffalograss did spread faster and more effectively than the cespitose blue grama in revcovering from the Great Drought of the 1930s from which the preceding experimental findings were derived.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.
27. Blue grama in early morning sun- An individual plant of blue grama at anthesis with early morning sunlight catching features of this bunchgrass just right. All blue grama shoots are tillers (upright, intravaginated) so this species is strictly cespitose. At end of an extremely wet growing season that extended from the preceding winter through until early autumn the blue grama plants featured in this section had a high proportion of their shoots progress to the sexual reproduction stage. This individual plant was at peak bloom-- and beauty.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.
28. A study in shoots- A single blue grama plant most of the shoots of which developed to the stage of sexual reproduction. A wet growing season preceded by a wet pre-growth (dormant) season were the major plant growing conditions responsible for such a high proportion of sexually reproductive shoots rather than the typical condition in which substantially fewer tillers progress to stages of inflorescence development and anthesis. Even under drier conditions, however, short-shoot grasses like blue grama have a higher percentage of their shoots that advance to flowering.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.
29. Racemes of blue grama- The inflorescence type in Bouteloua has traditionally been regarded as a raceme, but in more recent times it was often described as an inflorescence consistinf of "short, spicate branches" (Gould and Shaw, 1983, p. 298). The racemes of the Chondrosium section of Bouteloua the racemes (spicate branches of the inflorescence) have numerous pectinate (an adjective referring to packed, downward-oriented floral units like teeth on a comb) spikelets (Gould and Shaw, 1983, ps. 299, 380).
The anthers in these racemes were fully exerted and conspicuous.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; anthesis.
30. Textbook example of blue grama- Local stand of blue grama at late grain-ripe stage on the Rolling Red Plains. Although blue grama is primarily a bunchgrass it is not strictly cespitose as it frequently has "short, stout, rhizomes" (Gould, 1975, p. 351). Now that most (almost all) of the true and tallgrass prairies have been put to the plow, thereby eliminating most of the little bluestem on the continent, blue grama is probably the native grass that dominates more acres of range than any other species. Blue grama is arguably the single most important native forage grass in North America.aat the present time
Oldham County, Texas. Mid-July; onset of grain-shatter stage.
31. Blue on red- A few plants of blue grama (first slide) and their inflorescences (second slide) on Texas' Rolling Red Plains. The inflorescence type of blue grama traditionally was described as a raceme, one-sided spike or racemose spike (Hitchcock and Chase, 1950, p, 532), or, more recently, panicle of spicate branches (Gould, 1975, p. 336). Oldham County, Texas. Mid-July; onset of grain-shatter stage.
32. Blue grama in dormant stage- This is an example of dormant (and ungrazed) blue grama illustrating the "cured-on-the-vine forage" feature of this species. The specimen in this slide was at the extreme western edge of the Texas West Cross Timbers. Young County, Texas. April.
33. Racemes of blue grama- Even after a wet winter and almost midway into a Texas spring a few spikelets persisted on this blue grama raceme. Young County, Texas. April.
34. Galleta (Hilaria jamesii)- Galleta is one of two major Hilaria species on the Great Plains (H. belangeri being the other). This eragrostoid grass is either decreaser or increaser depending on range site. It is one of the more productive grasses on the "tight land" (high clay) ranges of the High Plains. It is also fairly palatable and overall one of the more desirable grasses on certain range sites and range types. For comparative purposes it is considerably more productive than buffalograss though it does not "cure" as well (retain nutrients in states of dormancy or semi-dormancy). For this reason galleta--as is typical of most Hilaria species--is quite unpalatable during late autumn through winter and into early spring.
The specimen(s) shown here was probably one (or two) clones of a large plant on an overgrazed and severely degraded range in the Rolling Red Plains of the southern Texas Panhandle. This provided a good example of the habit of this highly rhizomatous member of the Chlorideae tribe.
Scurry County, Texas. October. Phenology: entering dormancy, immediately following grain-shatter.
35. Galleta or galletagrass (Hilaria jamesii)- Galleta is often a locally dominant grass in the southern Great Plains, especially in the High Plains portion. It furnishes herbage having fair to good forage value but it is too restricted in distribution to be a major range species. Howard County, Texas. October.
36. Inflorescences of galleta- The spike-like inflorescence, a spicate raceme, of gallata in anthesis. Spikelets of the Hilaria species o ccur in groups of three that form bunches or clusters known as fascicles. This is a specialized arrangement with the fasicle interpreted as a false or quasi-involucre.
37. Curly mesquite (Hilaria belangeri)- Sward of curly mesquite. This is one of seven Hilaria species in North America, four of which are important range grasses. According to Gould (1951, p. 159) H. belangeri is the most palatable of these species, all of which are sod-forming (rhizomatous and/or stoloniferous). Curly mesquite has been the Hilaria species typically regarded by rangemen as a dominant of the "shortgrass country" (both shortgrass plains and overgrazed mixed prairie) and a species associated with such other shortgrass species as buffalograss and blue grama. Other vegetation specialists, particularly vegetation classifiers and mappers, in more recent works interpreted galleta (H. jamesii) as the dominant Hilaria on the Great Plains grasslands. For example, the Kuchler (1964, 1966) unit K-58 (Gramagrass-Buffalograss) did not list curly mesquite (Kuchler, 1964, p. 65). The Society for Range Management (Shiflet, 1994) did not even mention curly mesquite in descriptions of rangeland cover types SRM 705 (Blue Grama-Galleta) and SRM 715 (Grama-Buffalograss) of the Southern Great Plains Region. Dick-Peddie (1993, p. 104) gave galleta and not curly mesquite as the associate of the codominants, blue grama and buffalograss, of plains-mesa grassland. Curly mesquite does not grow in the central and northern Great Plains, but galleta occurs as far north as Wyoming so it is the Hilaria species sometimes found in rangeland cover type SRM 611 (Blue Grama-Buffalograss) of the Northern Great Plains Region.
In the experience of the current author omission of curly mesquite was somewhat erroneous, misleading to say the least. From his observations this author felt that Thomas (in Correll and Johnston, 1979, p. 11) was much "closer to the mark" when he listed curly mesquite immediately following buffalograss as a major increaser species on the Texas Rolling Red Plains portion of the Great Plains. Perhaps this was the reason why other (and more recent) authors did not list curly mesquite: it is an increaser and not a decreaser on most range sites (ie. it is not a climax species or a major species of the potential natural vegetation).
[By the way, this was still more evidence that SRM rangeland cover types typically resemble quite closely the climax or potential natural vegetation in spite of statements that explained SRM cover type "classification is based on existing vegetation" such that of these types "...most do not..." coincide with those of Kuchler (Shiflet, 1994, p. xi-xii). In fact the SRM rangeland cover types of the Great Plains province included essentiallly all of the Kuchler units of potential natural vegetation, and most of the other Great Plains rangeland cover types that did not correspond exactly with Kuchler units were smaller spatial subunits of these. One thing was certain: if qualifying statements given in Shiflet (1994, ps. xi-xii) were taken literally there would definitely have been far more reference to curly mesquite as well as a curly mesquite rangeland cover type. There are thousands of acres in the Texas Great Plains on which the dominant herbaceous species is curly mesquite, typically with honey mesquite as a scattered overstorey. This plains vegetation is a widespread form of depleted range: a seral stage on rangeland damaged by various combinations of former cultivation or "go-back land", severe overgrazing, oil and gas activity, and perhaps unique meteorological sequences of events or even climatic changes.]
The indespensible Pasture and Range Plants (Phillips Petroleum, 1963, p. 43) explained that curly mesquite had "increased and invaded ranges where better grasses were killed out by abusive grazing". Furthermore, curly mesquite is less palatable than buffalograss and blue grama and goes dormant earlier in drought all of which enable curly mesquite to survive "when better grasses die or thin out". While curly mesquite forms a dense sward such as the one shown here it's "forage production is very low when compared to the better grasses it replaced." (Phillips Petroleum Company, 1963, p. 43).
Regardless of successional status, forage value, soil cover, or usefulness as an indicator species, curly mesquite is-- for better or worse-- a nonclimax dominant on many ranges throughout much of southern Great Plains, a vast range region. In something of an overstatement when applied to the Rolling and High Plains Hitchcock and Chase (1950, p. 485) got the essence of the situation in regards curly mesquite: "Curly mesquite is the dominant 'short grass' of the Texas plains". (When the Rio Grande Plains are included this statement was "right on target".) Silveus (1933, p. 361) wrote that curly mesquite "is one of the most important grazing grasses on the Great Plains of Texas and New Mexico, extending into Mexico". Curly mesquite is commonly about the only perennial grass providing forage and soil protection over a large portion of Great Plains grasslands.
The examples in this section were from the Texas West Cross Timbers (Shally Hills range site) which is about the eastern limit of this species that is more typical of the semiarid zone. Erath County, Texas. Estival aspect in moderate drought, Late August.
38. Growth habit of curly mesquite- Typical appearance of curly mesquite plants. Parts of three stolons of curly mesquite (diagonally aligned from lower left to upper right). Erath County, Texas. Late August.
39. Typical curly mesquite plant- This unit of a curly mesquite clone showed the usual habit and leaf features of this shortgrass species. Erath County, Texas. Estival aspect, late August.
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40. Crawling across the rocks- Asexual (= vegetative) reproduction and the clonal structure of curly mesquite was obvious in this specimen as it sent out stolons and daughter plants over this sandstone. Note also however sexual reproduction by production of grain: "seed stalk" (culm with the fascicle arrangement of spikelets) in right foreground.
Erath County, Texas. Estival aspect in moderate drought, late August.
41. Curly mesquite runner- This stolon of curly mesquite had four daughter plants developing at nodes of the shoot. Curly mesquite is a clonal organism in which the genetic individual (the plant of an individual genotype) is the genet (= ortet) and the new daughter or sister plants are ramets (= modules) of the genet. Essentially all perennial plants are clonal organisms, but the new clones (modules or rametas) are very obvious-- hence the concept of clonal organization readily understood-- in sod-forming shortgrass species like curly mesquite and buffalograss.
Stolons are extravaginal shoots. They are secondary shoots arising out of the parent shoot (itself a secondary shoot-- as distinguished from the primary shoot that originated from the embryo asexual generations previously). In extravaginal shoots (which also include rhizomes) the new secondary shoots pierce or come up through the sheath, an organ of invaginated tissue (hence these piercing shoots are extravaginated). Intravaginated shoots are those which grow upward inside of (rather than piercing) the sheath. Intravaginal shoots are labeled tillers. Grasses whose secondary shoots are intravaginated (ie. tillers) have a tufted or cespitose growth form and are called "bunchgrasses". This is in contrast to "sod-forming grasses" like curly mesquite. (Some grasses like Indiangrass and many of the bluestems have both tillers and extravaginal shoots, especially rhizomes.)
Stolons and rhizomes are more effective than tillers in invasion of new ground by the genet (genetic mother plant). Said another way, extravaginal shoots are more efficient propagules for populating a plant's "resource frontier".
Erath County, Texas (Western Cross Timbers), Texas. Late August.
42. Curly mesquite module- "Close-up" view of a daughter plant (ramet or module) developing along a runner (stolon) which is an offshoot of the oretet or genet (the "original" plant of the individual genotype).
43. Curly mesquite spikes- Various portions of curly mesquite inflorescences were displayed for today's lecture. The infloresecence of curly mesquite (all Hilaria species for that matter) is a spike, an unbranched flower cluster-- the inflorescence-- in which the spikelets are sessile--without a pedicel or not pedicellate-- on the rachis. The rachis of curly mesquite is one of the most distinctive of any species of North American grass. It forms a right angle zig-zag pattern known to rangemen as the "crankshaft rachis".
Hilaria spikelets are arranged in fascicles, clusters or bunches, each of which (and each spikelet within which) is sessile. There are characteristically three spikelets per fascicle (two lateral spikelets, both of which have several florets that are each staminate, and a single central spikelet which is one-flowered and perfect).
Inflorescences in the second photograph were in various stages of maturity, including one that was immature (green).
Erath County, Texas. Late August, and after recent rains.
44. A midgrass amid shortgrasses- Some plants of Arizona cottontop (Trichachne californica= Digitaria california) growing among plants of blue grama (dominant) and buffalograss (associate) on the Southern High Plains (Staked Plaind= Llano Estacado). This bunchgrass is a midgrass species along with sideoats grama and western wheatgrass, Adult height of this midgrass was presented with shortgrasses, with which it is most frequently associated on the High Plains, for comparative purposes.
Arizona cottontop--the specific epithet is a commenrative name for Baja California (Barkworth et al., 2003, p. 368)-- is a decreaser that is frequently a major forage species on the mixed prairie. It is especially abundant and valuable in direr parts of the semiarid zone. It is also an important (locally dominant) climax grass on some ranges in the Chihuhuan Desert and, especially, the Sonoran Desert. In addition to standard treatments in the general literature both old as, for example, the Range Plant Handbook (Forest Service, 1940, ps. G122-123) and new as in Flora of North America- Poacaeae, part 2 (Barkworth et al., 2003) some of the most thorough descriptions have been those by Cable (1971, 1979), especially the former that was nearly monographic in coverage.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and grain-ripe phenological stage(s).
45. Cottontop is tops- Examples of the habit of striking features of Arizona cottontop at phenology of grain-ripe and peak standing crop. Specimens presented here were at end of one of the wettest growing seasons in years on the Llano Estacado and demonstrated the remarkable production of native grasses that occurs under such ideal conditions. Although Arizona cottontop is highly productive (in reference to its niche and production therein) it is most palatable when growing and does not "cure on the vine" (retain nutritive value in dead herbage) to the degree that associated grasses like buffalograss and blue grama do. As a deed- rooted perennial this midgrass member of the Paniceae (panicgrass tribe) is one of the most rapidly growing grass species in the spring.
This is not what most plainsmen mean when they speak of "tall cotton" in that part of the Southern High Plains which is one of the greatest cotton-growing areas on Earth. In a bowdlerized version of one of their colorful expressions, stockmen and other admirers of Great Plains grasslands are defecating "in tall cotton" when their stewartship permits Arizona cottontop like this to flourish on their ranges.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and grain-ripe phenological stage(s).
46. Emphasis on inflorescence- Two views of the inflorescence and the pubescent spikelets of Arizona cottontop to feature the general appearance and morphology of this panicoid species. With secondary branches coming off of the central axis of the flower cluster this overall inflorescence type (likemost others of the Paniceae) is a panicle, but the panicle branches were described by Hitchcock and Chase (1950, p. 570) as "slender erect or ascending racemes". Such a panicle of racemes is an unusual arrangement.
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; grain-ripe phenological stage.
47. Cotton in the tops- Basis of the common name "cottontop" is derived from the silky or cottony (and usually whitish) pubescence on the florets of the paired spikelets. Arizona cottontop generally produces modest to abundant crops of viable grain that are useful for reseeding. Natural Resources [Soil} Conservation Service Plant Materials (often in cooperation with other agencies and universities) have several releases of Arizona cottontop including PMT-389, LaSalle Germplasm, and Loetta. In such matters as reseeding, including selection of adapted species and accessions, the expertise of local authorities (eg. range conservationists, county agricultural agents and area Extension specialists, reclamation workers).
Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; grain-ripe phenological stage.
48. Squirreltail bottlebrush (Sitanion hystrix)- This member of the wheat or barley tribe is generally viewed as an invader or, at best, increaser on most range sites but it grows throughout a vast part of the Western Range including most of the Intermountain Region, Rocky Mountains, and Great Plains. Squirreltail is often common in the sagebrush shrub steppe, semiarid plains grasslands, and mountain grasslands and subalpine meadows. The range of bottlebrush extends from the Pacific slope to east of the Rocky Mountain chain and from British Columbia far down into the western states of Mexico, including Baja California. As might be expected from this great species range several varieties or subspecies of this species have been recognized. The awns of squirreltail have sometimes proved to mechanically injurious to animals, but generally this has been more nusiance than anything.
49. Silver bluestem (Andropogon saccharoides= Bothriochloa sacharoides= B. laguroides subsp. torreyana) at anthesis - This midgrass is typically an increaser on most mixed prairie range sites and an invader on tallgrass prairie range sites, but it is a decreaser on some range sites in drier parts of mixed prairie, the arid semidesert grassland, or shallower sites in the western Edwards Plateau adjoining the Chihuhuan Desert.
The conflicting interpretation of seral versus climax status of silver bluestem as well as varying descriptions of role and dominance this species in mixed paririe was presented below under Staked Plains mixed prairie. Stated summarily for general, across-the-board purposes and especially for lay audiences, silver bluestem (silver beardgrass) is an increaser when viewed "on average" over the extent of its biological (species) range, but for precise pruposes and in more scientific contexts successional (disturbance) status of silver bluestem is range site-specific such that this species is alterntively decreaser, increaser, or invader depending on the particular range habitat on which it is growing. While silver bluestem has often been regarded as a mid-seral species (Nofal et al., 2004), which equates to increaser in response to overgrazing, Clements (1920, ps. 132, 133, 134, ) and Allred (in Weaver and Albertson, 1956, ps. 270-272) interpreted silver bluestem as a decreaser and local climax dominant on certain grassland environments in the Great Plains, especially southern parts of the High Plains. In the semidesert grasslands Desert Plains) Clements (1920, ps.144, 146) interpreted (in his monoclimax model) little bluestem, silver bluestem, and sideoats grama as subclimax dominants" in the climax Aristida-Bouteloua Association. Later he (Clements, 1920, p. 323) cited results where other workers in the Sonoran Desert had obtained satisfactory results in range restoration by reseeding moist sites in which silver bluestem (the common names were silver-top or feather bluestem) was sowed along with blue, hairy, and sideoats gramas. Clearly silver bluestem cannot be sowngraded to increaser rank on more xeric range types and site.
In the encyclopedic Flora of North America (Allred in Barkewoth et al., 2003, p. silver bluestem was specified as B. laguroides whereas B. saccharoides has a species biological range farther south. By this latest treatment there is no B. saccharoides in the United States of America. It is all B. laguroides.
Erath County, Texas. July (lower photograph), late October (first or upper slide); full-flower phenological stage in both slides showing the opportunistic nature of flowering in this species. (Photographic note: the difference in color of herbage shown between these two slides is natural. Older plant tissue is silver bluestem takes on a darker green, less bluish cast).
50. Silver bluestem at peak biomass- Large individual of silver bluestem was at soft dough stage on an Edwards Plateau live oak-juniper mixed prairie savanna at (or near) climax. Another though smaller individual was at left foreground (lower left corner). This is the typical habitat of silver bluestem on mixed prairie.
Texas A&M University System Sonora Experiment Station, Edwards County, Texas. October.
51. Silver bluestem at seed ripe stage- Characteristic autumn coloration of this prairie midgrass. Note that most of the shoots are sexually reproductive. This sprawling habit is more characteristic of plants growing on tallgrass prairie. Erath County, Texas. July.
52. Partly in and out of the boot- The four apices of silver bluestem shoots in these two photographs presented four degrees of emergence of the inflorescence (panicle) from the boot. Panicle atop the left shoot in second photograph was fully emerged or exerted. Details of fully expressed panicles were shown in the next set of two slides. West Cross Timbers near end of a summer of severe drought.
Erath County, Texas. September, emergence of inflorescence from boot.
53. Silvery spectacle- No, not necessarily spectacular but a conspicuous spectacle nonetheless was this appearance of showy inflorescences of silver bluestem in the Western Cross Timbers. Terminology applied to inflorescences of Andropogon, Bothriochloa, Schizachyrium, and Dichanthium species has about as many interpretations as does taxonomy of these taxa. Contemorary description of this inflorescence type is panicle with primary racemose branches (Gould 1975, p. 591; Hignight et al., 1988, ps. 8, 23; Hatch and Pluhar, 1993, p.43). These specimens were growing in the West Cross Timbers near end of a long, hot sumer of severe drought and following two mowings. This species is survivor if given half a chance (come to think of, even if not given half a chance).
Erath County, Texas.September, fully emerged inflorescence, at 1) pre-anthesis stage (first photograph) and 2) early dough stage (second photograph).
Silvery details- Details of phytomers, including close-up views of the leaf sheath and axillary area (lower or second slide) of silver bluestem. The phytomer of a grass shoot is that unit encompassed by 1) the upper half of one node, 2)lower half of the next node up the shoot, 3) internode between these, and 4) attendant leaf.
Erath County, Texas. Late October. Adult plant stage of phenology.
54. Plains bristlegrass (Setaria macrostachya= S. leucopila)- Plains bristlegrass is another warm-season, panicoid, mid-grass species. Whereas the preceding silver bluestem was in the bluestem tribe (Androogoneae) the Setaria species are in the panicgrass tribe (Paniceae). There are both annual and perennial Setartia species with almost all of the former being weedy in contrast to the typically climax perennials, most of which are cespitose (tufted or bunchgrass) species. Setaira species--both annual and, especially, perennial species--generally produce relatively abundant and palatable forage. Plains bristlegrass is the most important of the Setaria range species in the mixed prairie, especially on the Southern Great Plains, including the Llano Estacado or Staked Plains (see that section in the chapter, Mixed Prairie-I, Southern and Central Great Plains).
Plains bristlegrass is a diverse group of taxa that form a complex including S. macrostachya, S. leucopila, and S. texana (and perhaps others). Hitchcock and Chase (1950, ps.721-722, 952) used S. macrostachya as the binomial for this complex that Gould (1975, ps. 537-538) separated into the three above listed species. Barkworth et al. (2003, ps. 546-549) also recognized these three species, but specified that S. leucopila "is the most common of the perennial 'Plains bristlegrasses'".Long before this, Silveus (1933, p. 674-675) published Texas Grasses , the first encyclopedia of Texas Gramineae and usedthe scientific name, S. macrostachya listing Chaetochlora macrostachya and C. composita as synonyms. In their now classic Flora of New Mexico Wooton and Stanley (1915, p. 60) recognized this (these) species as S. composita (= C. composita). Earlier in the also classic Botany of Western Texas Coulter (1891-1894, p. 510) used S. caudata. Ivey (2003, p. 497) used S. leucopila for plains bristlegrass in New Mexico, but of course S. macrostachya is also in New Mexico. Both of these species are also native in Mexico.
Whatever the nomenclature and arrangement, the plains bristlegrass complex is comprised of plants that are quite valuable as decreaser forage species throughout much of southwestern North America. They produce abundant and palatable herbage (especially by panicoid standards) that is readily available as range feed for grazing animals.
Plains bristlegrass is a major range plant up through associate to dominant species on numerous range sites in southwestern North Amreica.
The green shoots of the specimens presented here included both 1) older (early season) shoots, upper portions of which were sexually mature and going senescent (ripe caryopses) and 2) late-season shoots, the new growth of which was made possible by recurrent heavy rains.
Quay County, New Mexico. Mid-July, grain-ripe phenology.
55. Ripe grain of a mid-grass- Contracted panicles loaded with mature caryopses of plains bristlegrass. The comparatively large fruit of this panicoid species are well adapted to Mother Nature's propagation of this native of the arid and semiarid Southwestern Range Region. These inflorescences were on the specimen presente in the preceding photographs.
Quay County, New Mexico. Mid-July, grain-ripe phenology.
56. Buffalograss- The quintessential shortgrass species in full bloom (staminate inflorescences)- Buffalograss is the co-dominant with blue grama over much of the Great Plains region, especially the potential natural vegetation of the semiarid central grassland domain identified as "Grama-Buffalo Grass" (K-65 in Kuchler, 1964; K-58 in Kuchler, 1966).
It was described above when introducing blue grama that this cespitose (bunchgrass) species and buffalograss are co-dominants yet blue grama is considerably more drought tolerant than buffalograss. During recovery from drought the stoloniferous buffalograss restores its cover faster than the strictly tiller-producing blue grama. The affilitation, interaction, and response to drought of buffalograss and blue grama were chronicled by Weaver and Albertson (1956, ps. 33, 79, 104,133, 149-150, 253-254.
As with blue grama, buffalograss has received treatment in all of the major taxonomic and ecological works, both scientific and lay publications (and those in between).
Erath County, Texas, May.
57. Shooting up shoots- A plant of male buffalograss with numerous sexual shoots (staminate shoots in case of this male plant). This dioecious species reproduces both sexually and asexually, this latter mode mostly via stolons although rhizomes are produced infrequently. The clonal characteristic of buffalograss is pronounced with sizeable areas (often measured in hundreds of square yards) of the soil surface covered by a single plant. Adventituous rooting at nodes along stolons gives rise to many "daughter" or "sister" plants (modules, ramets, or clones) of the original parent or "mother" plant (the unique geontype). Each of these modules in turn gives rise vegetatively (asexually) to still more modules or clones (=modular or clonal plants) each of which can send up sexual shoots of the same same sex as the genotype (ie. many staminate or pistillate shoots per module) of each individual of this dioecious species.
Erarth County, Texas. May; anthesis.
58. Male buffalograss- Buffalograss is regarded as being either monecious or dioecious. If the latter is the case then the specimen in this slide is a staminate plant, but either way the inflorescences are staminate. A stolon or runner was presented in the lower left foreground to illustrate asexual reproduction along with the sexual mode. Buffalograss is one of the best examples with which to illustrate the phenomenon of a clonal organism. Each of the nodes along the stolon can produce a new daughter plant thus making the older clonal unit the mother or parent plant.
Tarleton State University Hunewell Ranch, Erath County, Texas. May.
59. Study of a buffalograss ramet (and of photographic light)- Paired photographs of a vegetatively reproduced unit (a ramet or clone) of a genetic individual (genotype) of buffalograss. This pair of photographs (one on left was in full-sun; one on the right was under overcast sky) presented certain features with more clarity in either full-light or some degree of shade. This paired comparison was study of lighting conditions for revealing photography as well as the primary objective of showing a dominant shortgrass species.
Erath County, Texas. October; anthesis.
60. Clonal unit of buffalograss- Sexual shoots fully emerged on one vegetative unit (a clone) of male buffalograss. Sexual and asexual reproduction were both presented in these two photographs. Buffalograss typically blooms in both mid-spring and mid-autumn, but it is opportunistic and reproduces sexually when growting conditions (especially soil moisture) permit. (Note the various months of blooming represented by various photographs in this section.)
Erath County, Texas. October; anthesis.
61. Staminate flower clusters of buffalograss- Views of male inflorescences of buffalograss that developed in late summer in response to the blessings of good rains that fell in late summer and with above average temperatures.
Tarleton State University College Farm, Erath County, Texas. September, late summer.
62. Bull buffalograss in rut- Anthesis in staminate flowers of buffalograss. Like most of the native grasses of the semiarid plains buffalograss has to be opportunistic, especially with regard to sexual reproduction. The male inflorescences presented here and in the preceding slides were blooming in late summer following recent rains.
First photograph: Erath County, Texas, May. Second photograph: Tarleton State University College Farm, Erath County, Texas, September, late summer.
63. Close-up view of staminate inflorescences of buffalograss- Male inflorescences of buffalograss have the typical raceme of members of the Chloridae tribe. Students should note the raceme shared by such members as the grama grasses, cordgrasses, windmillgrasses, crabgrasses, bermudagrass. Tarleton State University Hunewell Ranch, Erath County, Texas. May.
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64. Buffalograss- An individual buffalograss plant with pistillate inflorescences (caryopses in soft dough stage). Erath County, Texas. May.
65. Buffalo gals in full-bloom- Sexual shoots of female buffalograss with exerted stigmas. Erath County, Texas. May, mid-spring.
66. Burrs of buffalograss- The one-flowered pistillate spikelets of buffalograss occur in groups of three up to six or seven each of which is surrounded by glumes that form an enclosing, hard, globular burr. Erath County, Texas. May.
67. Springing forth-Young spring stolons of buffalograss with typical coloration of early growth and arrangement of leaf axils on shoots.Stolons are aboveground intervaginal (piercing of leaf sheath) shoots. All intervaginal shoots, of which there are two types in grasses (rhizomes being the other), are horizontal. This is in contrast to intravaginal shoots (= tillers) that grow vertically and up through (rather than peircing) the leaf sheath.
Tarleton State University College Farm, Erath County, Texas. Late April; vigerous spring-growth (shoot elongation stage).
67. Both modes of reproduction- All-in-one views of male and female inflorescences as well as sister or clonal units on stolons (first slide) and closer-in view of clonal units (second slide) of buffalograss. The clonal units are known variously as modules; ramets; daughter units; or, simply, clones. The numerous clones shown had formed at nodes and were developing adventituous roots at these modules.
Erath County, Texas. Mid-October; peak standing crop and full development of sexual and asexual organs.
68. Surviving drought on the Great Plains- Several plants (or modules,clones of the same genetic individual) of buffalograss undergoing drought stress in early spring. It is usually assumed that nonwoody grasses (ie. all but bamboo) do not have aboveground perenniating parts; that is, all shoots are only annual organs that die at end of the annual growth cycle. This is mostly true, however some species like buffalograss have shoots that sometimes live for two or even three years with periodic bouts of dormancy. Drought and temperatures below the critical temperatue are two dormancy inducers.
The shoots (culms and leaves) of the buffalograss presented here had some parts that were apparently dead and others that were obviously alive. It provided a good example of the "Is it alive or dead?" state of this eragrostoid species. Clearly this is a survival adaptation for grass life on the plains. A dramatic lesson if life, especially for such a short plant.
Central Plains Experiment Station, Washington County, Colorado. Late June: drought-stressed.
69. "Cured on the vine"- A combination of small, fine leaves tht tend to retain the nutritive content, dry winters in the semiarid zone with limited moisture to leach out nutrients in plant tissues, and stolons that can live for more than one growing season (or year) result in dry, brown, and apparently "dead" (or nearly so) buffalograss shoots (stolons) that are remarkably nutritious and palatable in winter (or whenever dormant). This phenomenon of self-cured, dried herbage of remarkable high nutritive value on the Great Plains (even in winter) was recorded (with reliance on written correspondence) in one of the enduring classics of the Western Range livestock industry: Trans-Missouri Stock Raising The Pasture Lands of North America: Winter Grazing (Latham, 1871; reprinted with an introduction by J.C. Dykes, 1962, ps. 15-21, 78, 80,81, 86). A few excerpts included: "... the grasses cure on the ground without losing any of their nutriment..." (p. 18), "... subsisting upon the natural grasses of the country, in the winter as well as summer; no preparation of hay or other food is necessary" (p. 78), and "[t]he grasses are highly nutritious, cure on the ground, remain as permanent food during the entire winter..." (p.80).
Of course the Great Blizzard of 1886 ended the "no hay-era" when snow and ice covered the shortgrasses (made shorter still by overstocking) terminating in the great "die-ups", but that disaster bred out of ignorance, glib optimism, and greed did not negate the fact that when herbage of range grasses, like buffalograss, was available it retained its nutritional quality even in winter.
Las Animas County, Colorado. Late June: atypical stage of growth due to drought dormancy.
70. Sward of inland or desert saltgrass (Distichlis stricta)- This is a colony of male plants of this dioecious species. It completed its yearly life cycle on a saline flood plain in the most extreme drought to-date in Colorado history (2002). Flood plain of Horse Creek, Crowley County, Colorado. June.
71. Male inflorescence of inland saltgrass- The staminate flower cluster of inland saltgrass at anthesis with stamen clearly visible. Horse Creek flood plain, Crowley County, Colorado. June.
72. Wolftail (Lycurus phleoides)- Wolftail (literal translation from the Greek base, Lycurus) is in the Aveneae (oat or, sometimes, timothy) tribe. In fact, wolftail has the less-used common name of Texas timothy. The infloresence is a contracted panicle. This perennial bunchgrass has shoots that have been described as "semiperennial" (Forest Service, 1940, G77), the phenomenon in which the tillers frequently proceed only to partial dormancy and death during winter therby allowing rapid spring green-up with onset of rains and warmer temperatures. Similar phenological responses occur in buffalograss and blue gramma, two associated species on the plains grassland and southwest pine forests in which these species occur. All three species possess the desired forage feature of curing at a relatively high state of nutritive value (ie. the capacity to "cure on the vine" discussed above). (Of course gramagrasses and buffalograss are eragrostoid while wolftail is a festucoid grass.)
The specimen photographed here was part of the understorey of a juniper woodland in the Mogollon Rim country of central Arizona (Yavapai County). Mid-June of a dry spring and before onset of summer rainy season, but in worst drought in Arizona history (exceptional drought). The "semiperennial" condition of wolftail tillers (bluish gray color) was visible in both slides.
Examples of purple threeawn (Aristida purpurea) from disturbed ranges of tallgrass prairie were presented here as examples of plants in this widespread taxonomic complex (explained in the next photo-caption). Following samples of purple threeawn from the tallgrass region examples from the mixed prairie and shortgrass plains were introduced.
Successional ranks (statuses in response to range distrubance, especially overgrazing) of Aristida species, and in particular the various taxonomic forms (varieties or whatever) of A. purpurea, remain incompletely understood and a topic of continuing controversy. It is "textbook knowledge" that threeawns are invaders on most North American grasslands and, except in rare instances, of other biomes (presence of Aristida species on desert and southern pine forest ranges are notable exceptions) Threeawns are "textbook examples" of plant indicators of severe range disturbance and deterioration (improper grazing management, tillage and subsequent abandonment of cropland, "cut-and-run" logging) such that various species of threeawns or wiregrass are abundant and widespread on overgrazed ranges, old fields ("go-back land"), and cutover forests.
This generalization is adequate for basic textbooks (at least some of them), Agricultural Extension fact sheets, conservation agency brochures, and ranchers' guides. Beyond these, however, the successional meaning and even practical importance of threeawns on grassland ranges is far from clear or straightforward. One of the common observations in plant succession and development of range vegetation is that species that tend to increase on or invade disturbed plant communities (=abused or degraded ranges) in humid and subhumid regions frequently dominate ranges in climax or high seral stages (and decrease or even disappear from these same ranges when they are severely disturbed) in semiarid and arid regions. In other words, range plant species that are decreasers in more xeric (and otherwise harse) range environments are increasers or invaders on range habitats found under more mesic (less severe or more moderate or amenable) conditions. A number of the Aristida species appear to show such responses.
Clements (1920, ps. 115, 119, 121) interpreted A. purpurea (or equivalent Aristiada species) as potential natural dominant species along with little bluestem, sideoats grama, and certain needlegrasses in the general or regional Stipa-Bouteloua Formation, including the portion of tallgrass prairie (the Andropogon associes in context of monoclimax theory) therein. While he noted that Aristida species were some of colonizers or early invaders on overgrazed grasslands and abandoned fields he also explained that A. purpurea was an associate of buffalograss, galleta, and tobosagrass in the Staked Plains of Texas and a species associated with blue and black gramas in the Chihuhuan and Sonoran Deserts of New Mexico and Arizona (Clements, 1920, ps. 142, 144). Clements' Desert Plains climax grassland (known currently as semidesert grassland) was the Aristida-Bouteloua Association in which there was a consociation (a climax unit comprised of a single species-dominant) each for A. purpurea, A. californica, A. arizonica, and A divaricata as well as consociations of bush muhly along with those of black, blue, sideoats, Rothrock, and hairy gramas.(Clements, 1920, p. 145 and still more on 146-148).
Conversely, Clements (1920, ps. 95, 140) also recognized that Aristida species did invade overgrazed grassland and abandoned cropland. Perhaps the observations and descriptions of Clements (1920, above cited pages) are consistent with and even serve as an exampe of patch dynamics. If this was the situation, certain Aristida species such as purple threeawn would serve as early invaders of disturbed patches (overgrazed spots for example) with presence of this species reflecting (indicating) disturbance gaps in the grassland sward. Even if that explanation is correct it remains only a partial explanation. Given that Clementsian consociations were units of climax vegetation (vegetational components of an association, an association comprised of a single dominant species), species that formed consociations had--by definition--to be climax and therefore correspond to decreasers and certainly not invaders.
Organization Note: Viewers can read in Literature Review (Range Type section or heading, Historical Note: "Founding Fathers" of Range Management subheading thereunder) where the Dykersterhuis (1949) decreaser-increaser-invader model was derived in large measure from the plant indicators concept of Clements(1920, especially Section VI. Grazing Indicators, ps. 270-335). Therein it was noted that it was Plant Indicators that provided the germ of the Dyksterhuis (1949) categories of decreasers, increasers, and invaders in the concept of seral types as grazing indicators.
73. Perennial threeawn (Aristida purpurea) on deteriorated tallgrass prairie range - What is most likely "purple threeawn" was thriving and adding spring color to an area heavily impacted by motor vehicle traffic.This was typical "prime habitat" for threeawns which are some of the most abundant perennial grasses on the most abused areas (eg. sacrifice areas, "stomp lots", ranch roads). The other most common species on this deteriorated site was the naturalized alien, rescue bromegrass. The threeawns or "wiregrasses", as they referred to in the southeastern pine forests, are typically classified successionally as invaders. As a general rule Aristida species are characteristic of vegetation at some stage of retrogression and therefore indicator plants of deteriorated ranges (or regenerating pine forests in less advanced seral stages). One of the general features of species responding as ecological invaders is low feed value. This is most pronounced in annual species, but some perennial species (in fact, entire genera) have this feature. Aristida is one of these (with some rare exceptions). In fact, there is a high proportion of Aristida species that are annuals, even short-lived annuals known as ephemerals.
As if all this were not enough, Aristida includes several taxa that are a taxonomist's worst nightmare. Some of these integrade or hybridize (or whatever grass plants do "to make life harder for agrostologists") with the result that various authorities have interpreted such taxa as species, subspecies, and varieties in different ways which has led to confusion and frustration (especially because the taxonomic arrangements seem to change with every new treatment of Aristida). The term that has often been invoked in describing and arranging these taxa into groups is "complex". An example of such includes such closely related and intergrading threeawns as red threeawn (A. longiseta), purple threeawn (A. purpurea), wright threeawn (A. wrightii), roemer threeawn (A. roemeriana), and a few others depending on which of these species grow in association in any given geographic location. In Texas the complex is often known simply as "perennial threeawn" or, sometimes, "purple threeawn" after A. purpurea which is viewed as the species, with what have previously been interpreted as separate species ranked as varieties therein. Thus "perennial or purple threeawn" includes A. purpurea var. longiseta, A. purpurea var. purpurea, and A. purpurea var. wrightii. Other agrostologists still designate these threeawns known by the various common names as separate species. There was bound to be some sort of lesson in this example of "where the experts cannot agree".
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74. Examples of perennial threeawn- These photographs displayed some individual plants that were typical of "perennial threeawn" (A. purpurea complex) in the Cross Timbers and Prairies vegetational area of northcentral Texas. Aristida species are strictly cespitose (= bunchgrass or tufted) species that produce only intravginated shoots (tillers) and no extravaginated shoots (stolons and rhizomes). There are some species in Sporobolus, Muhlenbergia, Festuca, and Andropogon (among others) that also have the cespitose habit, but in North America Aristida is probably the most extreme case of this. The tufted habit was very obvious in these examples.
75. More sun-faded than red (but alive)- Two plants of red threeawn (Aristida longiseta) on mixed prairie during a bad drought. Almost miraclously these two individuals were still alive and growing albeit it slowly. A. longiseta is the dominant threeawn or wiregrass over most of the mid- and shortgrass range of the Great Plains (Weaver and Albertson, 195.p, 41-43). What has traditionally been regarded as red threeawn has a biological range extending throughout the Great Plains and parts of the western Central Lowlands physiographic provinces as far north as the Canadian Prairie Provinces. This species also grows throughout much of Arizona and southeastern California, including the Sonoran Desert. (An example of red threeawn in the ponderosa pine forest range above the Sonoran Desert was presented in the chapter, Southern and Central Rocky Mountain Forests). Red threeawn has an amazing species range and degree of adaptation.
The Aristida species are a taxonomist's nightmare. The genus have been reinterpreted at various times. The most recent--and probably the official treatment for decades-- was that of Barkworth (et al., (2007, ps. 330-334) in which red threeawn was regarded as merely a variety of purple threeawn (Aristida purpurea): Aristida purpurea var. longiseta. What do you bet that this is not the final word either? Iin this new taxonomic treatment the traditional purple threeawn became A. purpurea var. purpurea. Other varieties in what was now termed the "A. purpurea complex" (Barkworth et al., 2007, ps. 330-334) included Fendler's threeawn ( A. fendleriana) which became A. purpurea var. fendleriana. Fendler's threeawn was presented and covered below.
Rnge Plant Handbook (Forest Service, 1940, p. G20) provided its typical concise yet thorough discussion, including practical considerations, of red threeawn.
Las Animas County, Colorado. Late June.
76. Reflecting sunlight to the namesake color- Specimens of red threeawn (A. longiseta) on a disturbed postclimax tallgrass prairie. On former tallgrass prairie in the Nebraska Sandhills herbiverous activity of black-tailed prairie dog (Cynomys ludovicianus) degraded the range into a patch of Eurasian weeds with red threeawn about the only perennial grass species still present. Some of those specimens, including the pretty individuals shown here, served as good examples of their species. (The case of prairie dog degradaation of tallgrass prairie was included in the chapter entitled, Tallgrass Prairie [Interior].)
Traditionally all of the Aristida species, including A. purpurea and A. longiseta, have been classed as invaders throughout the tallgrass through to shortgrass prairies. This is probably--perhaps definitely--an oversimplification that is frequently in error. Certainly these are relatively unpalatable species such that under heavy use, and even more so under overgrazing, persist after palatable species (hence, decreasers and increasers) have declined or disappeared. So far, so good. However, on mixed prairie these Aristida species recover from disturbances such as drought much like palatable short-and midgrass species (Weaver and Albertson, 1956, ps.143, 150). Likewise, Weaver and Albertson (1956, p. 213) reported that purple threeawn was less resistant to drought, a characteristic shared with tallgrass species (and not a feature characteristic of invaders). They also reported that A. longiseta was abundant on mixed prairie on the Colorado Piedmont where blue grama was dominant, in the blue grama-buffalograss shortgrass type, as a dominant midgrass species in the intermediate wiregrass type, and as an important species with the tallgrasses (including sand bluestem and prairie sandreed) in the bunchgrass type all in Colorado (Weaver and Albertson, 1956, p. 233, p. 241, p. 244, p. 246, respectively). Also in Colorado, red threeawn was associated with western wheatgrass and needle-and-thread on excellent shortgrass range dominated by blue grama and buffalograss (Weaver and Albertson, 1956, p. 255). All-in-all this is not the response or "friendships kept" by invaders, at least not on mixed prairie. It is quite another thing on tallgrass prairie as shown here on a prairie dog town on depleted postclimax tallgrass range.
Fort Niobrara National Wildlife Refuge, Cherry County, Nebraska. Late June; peak standing crop, soft dough phenological stage.
77. Fendler's threeawn (Aristida fendleriana= A. purpurea var. fendleriana)- A local stand of Fendler's threeawn on go-back land. Most Aristida species are invaders with disturburbances being the conditions under which most threeawn individuals grow. Notwithstanding this situation, Fendler's threeawn is widely distributed and adapted to a variety of conditions ranging from alpine to southwestern desert to old fields of the Great Plains (Silveus, 1933, p. 338; Forest Service, 1940, ps. G19-G20; Hitchcock and Chase, 1950, ps. 476-477; Gould, 1975, p. 400; Barkworth et al., 2003, ps. 332, 334). An example of a stand of this species on an old field in the Staked Plains was shown here.
Fendler's threeawn has been treated variously by various authors (discussed in the next caption) perhaps because it is a variable taxon (whether regarded as species or variety). It is frequentlly distinguished by a pronounced "pin cushion" form of basal leaves, but this is not consistent as Fendler's threeawn is similar (and sometimes confused) with red threeawn (A. longiseta= A. purpurea var. longiseta) or other taxa in the A. purpurea complex (next caption). One of the most obvious features of Fendler's threeawn--in addition to shorter awns (Allred, 1984, p. 393-394; Powell, 2000, p. 252) and solitary spikelets (Silveus, 1933, p. 337--is the overall short stature of individual plants of this species. In the extensive stand presented here there was not one plant over ten inches tall and most individuals were only five to seven inches in height. A. purpurea var. longiseta, which is extremely variable, has some individuals with heights as short as A. purpurea var. fendleriana (Allred, 1984, p. 393-394), but again the relatively shorter awns coupled with basal leaves and generally short stature distinguished plants presented here as Fendler's and not red threeawn.
Lubbock County, Texas. October. Fruit-ripe stage.
78. Sundown on Fendler's threeawn- The right light at the right time for the right species is one of the secrets to plant photography. "Fools luck" in this case was responsible for this photographer capturing Fendler's threeawn near sundown when long shadows luckily caught the distinctive awned appearance and general morphology of this High Plains species of Aristida. Aristida is one of the Gramineae genera that is generally an agrostologist's nightmare. Luckily (again for this author) A. fendleriana, with its short basal leavesand generally short stature, is one of the more easily identified species in a genera filled with contradictions and taxonomic complexes.
This is also one of the Aristida species that has consistently (more-or-less) been recognized by the various agrostologist specializing in this problematic genus. A. fendleriana has been ragarded as a "traditional species" (though "somewhat weak and controbersial") according to Powell (2000, p. 250). Recent work, especially by Allred (1984), resulted in reinterpretation of this taxon as another variety of the A. purpurea complex. This work was retained by the encyclopedic Flora of North America- Poaceae, part 2 (Barkworth et al., 2003, ps. 332, 334) in which the treatment of Aristida was by Allred. Either way, anyhow, etc., the taxon that still bears fenlderiana (somewhere) is interpreted as existing. It was shown here.
In the Range Plant Handbook the Forest Service (1940, ps. G19-G20) noted that this species (as interpreted therein) was also called "small triple-awn" and by stockmen as "no-eat-um-grass". Not only is this species fairly unpalatable but it produces even less forage than other associated three-awns. One of these associated (and closely related) Aristidas is A. longiseta or, in latest treatment, A. purpurea var. longesita from which A. purpurea var. fendleriana is distinguished by the much longer awns in longiseta. Essentially all of the taxonomic treatments cited herein (Silveus, 1933, p. 338; Forest Service, 1940, ps. G19-G20; Hitchcock and Chase, 1950, ps. 476-477; Gould, 1975, p. 400; Allred, 1984, ps. 393-394; Barkworth et al., 2003, ps. 332, 334) to some degree or the other indicated the short stature of this taxon compared to others in the A. purpurea complex with which it is closely related and morphologically similar to.
Lubbock County, Texas. October. Fruit-ripe stage.
79. One of the lowest and the lowliest- Hairy tridens (Tridens pilosus= Erioneuron pilosum) is a one of the few species of native, perennial grass that is almost always an invader no matter what range site it occupies. This low-growing species comes in (sometimes as a local dominant) of some of the most abused ranges and the harshiest of habitats. It is also one of those species for which the agrostologists cannot decide on its one correct (or most nearly correct) scientific name. In fact, they cannot even decide on its standard common name. Several of the various agencies of the United States Department of Agriculture showed the stupidly duplicitous common name of "hairy woollygrass". Why not "wooly woolygrass"? That would be more poetic; at least it it would not confuse two types of pelage. A literal interpretation of erion is Greek for "wool" and, of course, pilosus, pilosum, etc. is Latin in reference to "hair", or "or hair". Hence "hairy woolygrass". This, however, an example where literal translantion from one language to another results in nonsense, awkward, or downright stupid verbage; a logical extension beyond what is rationale, tasteful, or even meaningful. It is an example that the only trully universal scientific language is mathematics.
Hairy tridens is common--under disturbance--on tallgrass, midgrass (mixed), and shortgrass prairies as well as on pinyon-juniper woodland range. The specimen shown here was growing on an overgrazed range of disturbed tallgrass Grand Prairie. This individual was larger than most plants on mixed prairie or the shortgrass plains.
Erath County, Texas. April. Soft-dough stage.
80. Dead-give-away- Basal parts of shoots of hairy tridens showning the characteristic white-outlined leaves, a telltale feature quickly learned by beginning students. These leaves were on the plant introduced in the two immediately preceding slides. Erath County, Texas. April. Soft-dough stage.
81. Hairy tridens in the shortgrass country- Previous examples of hairy tridens were taken from disturbed areas on tallgrass prairie. This specimen was growing in the heart of "shortgrass country" and was included to present an example from some of its other preferred habitat where it kept company with buffalograss and blue grama. This shortgrass species is usually classified as an invader on most range sites. It is most common on overgrazed range or otherwise disturbed land (eg."go-back land") on tallgrass, mixed, and shortgrass (plains) prairies, but here on the shortgrass plains it was right at home where it can be an increaser depending on the range site.
Palo Duro Canyon State Park, Randall County, Texas. June.
82. Showy interloper on the sea of mixed prairie- Robust plant of the Eurasian, annual bulbous bluegrass (Poa bulbosa) that invaded a locally disturbed patch in the sward of a mixed prairie range in "mint condition" (Excellent range condition class; SRM 608) that was dominated by needle-and-thread, blue grama, and western wheatgrass. Bulbous bluegrass is sometimes a short-lived perennial (on some parts of California having Mediterranean climate), but it is a cool-season annual throughout the Great Plains and Intermountain Region. The competitiveness of this aggressive invader on disturbed sites and microsites was shown by presence of this species on a mixed prairie at climax except for local spots of disturbance the cause of which was unknown..
Niobrara County, Wyoming. Late June: peak standing crop at grain-shatter stage of phenology (and death of plant= completion of life cycle in an annual species).
83. Namesake bulbs and bases- Rootcrowns on some plants of bulbous bluegrass illustrating basis of the specific epithet, bulbous, (and, thus also, common name) of this aggressive Eurasian grass. Niobrara County, Wyoming. Late June: peak standing crop of dead plants.
84. Eye-catching panicle of a noxious species- Details of panicle of the Eurasian bulbous bluegrass. This was a close-up view showing spikelets in one of the panicles on the plant above the caption before last (two slide-set).
Niobrara County, Wyoming. Late June: grain shatter stage.phenology.
85. Plants and a panicle- Portions of five plants of Indian ricegrass growing in a consociation of this species that comprised a semidesert grassland in northern San Luis Valley were presented in the first photograph. Second photograph was a part of a panicle of one of these plants showing the tremendously heavy grain crop produced in an extremely wet growing season. These plants and those shown in the immedately preceding photograph of the above pair of slides were giant specimens of their species growing on pristine (Excellent range conditin class) semidesert grassland that was made up almost exclusively of this one species.
Alamosa County, Colorado. Mid-June, hard-dough phenological stage.
86. Ripening rice crop- Spikelets of Indian ricegrass on the widespread panicles typical of this species. Not typical was the extraordinarily heavy yield of grain that was produced in an unusually wet spring. Alamosa County, Colorado. Mid-June, hard-dough grain stage.
87. Sandhill muhly (Muhlembergia pungens)- Examples of this highly cespitose, eragrostoid grass growing on a dune form of mixed prairie that was a shrub-grassland of Indian ricegrass, blue grama, sandhill muhly, ring muhly, and needle-and-thread with black greasewood as the woody component.
Alamosa County, Colorado. Late June (early summer), approximate mid-growth stage of phenology.
88. Threadleaf sedge (Carex filifolia)- Threadleaf sedge is probably the single most abundant and important Carex species on North American ranges, at least in the continental interior. It is also one of the most widely distributed with a species range from the Yukon Territories to Texas and from the Pacific Slope east to Labrador (Forest Service, 1940, GL5; Fernald, 1950). Not only is threadleaf sedge valuable for grazing (Fair to Good forage value), it is also invaluable for prevention of soil erosion in the windy, semiarid Great Plains and in northern portions of the Central Lowlands. A good general reference for C. filifolia is (Hurd et al., 2998, ps. 112-113).
The plants presented in these and the next two photographs were taken on the "mint condition" (Excellent condition class) needle-and-thread, blue grama, and western wheatgrass-dominated range in the Central Great Plains that was featured earlier in this chapter (above). Threadleaf sedge and Indian riecgrass were associate range plant species on this range. Niobrara County, Wyoming. Late June; peak standing crop at mature fruit stage.
89. Shoot apices of threadleaf sedge- Sexual shoots (first photograph) and inflorescences, entire and fruit-ripe stage, (second photograph) of threadleaf sedge growing on an Excellent condition class range in Central Great Plains in which this species was an associate (along with Indian ricegrass) to needle-and-thread, blue grama, and western wheatgrass.
Niobrara County, Wyoming. Late June; peak standing crop at mature fruit stage.
90. Scarlet Globemallow (Sphaeralcea coccinea)- This member of the Malvaceae (mallow family) is often the most abundant forb in western portions of the mixed prairie and on into the shortgrass plains. There appears to be some dispute as to the forage value of this forb. It was described by the Society for Range Management Intercollegiate Range Identification Contest committee (Stubbendieck et al., 1982) as having but fair to almost no palatability, but in a later edition the committee (Stubbendieck et al.,1992) described it as excellent for native small ruminants. Hermann (1966) reported forage values ranging from poor or none to good. Observations by New Mexico workers on the blue grama ranges of the Ft. Stanton Experimental Ranch suggested that scarlet globemallow was quite palatable not only to forb-preferring animals like sheep and mule deer but also to cattle (specifically large stocker steers). Either (or any) way it is one of the more common forbs on plains and mesa grasslands.
Guadalupe County, New Mexico. June.
91. Broadleaf milkweed (Asclepias latifolia)- This is one of the more than two dozen species of Asclepias growing on the prairie and plains grasslands of the continental interior. It is one of the more common milkweeds on the Great Plains grasslands. There is amazing variation in the morphological features and preferred habitats of Asclepias species. One of the most obvious differences among milkweed species is in their leaves. Kingsbury (1964, p. 267) used the two divisions of: 1) narrow-leaved milkweeds (having "linear or narrowly lanceolate leaves") and 2) broad-leaved milkweeds ((usually greater than 1.5 inches wide over "much of their length"). Broadleaf milkweed is the accepted or preferred common name for A. latifolia which should not be confused with the general category of "broad-leaved milkweeds". Broadleaf milkweed was listed by Burrows and Tyrl (2001, p. 126) as one of 16 Asclepias species that are "particularly important toxicologically". The "poisonous principle" (ie. the toxin) is a group of organic compounds known as cardenolides which manifest themselves within the gastrointestional tract as well as by bleeding in trachea, lungs and the heart surface (Burrows and Tyrl, 2001, ps. 131-135).
***Note to beginning range students: While livestock losses due to poisonous plants may not be one of the major sources of losses industrywide, the importance to indvidual stockmen can be (often is) staggering. Like damage inflicted by predators, poisonous plant losses capture the attention, imagination, anger, and political action of livestock producers. Range Management professionals who work closely with stock-raisers (eg. Agricultural Extension agents, federal range conservationists, and agro-chemical product salesmen) should thoroughly familarize themselves with the fundamentals of the poisonous range plant problem. In range areas having histories of livestock losses (this includes any number of syndromes of lowered animal performance in addition to outright animal death) the range practitioner should cultivate a sound professional relationship with a veterinarian knowledgable in the field of poisonous plants. The earliest Range Management textbooks (eg. Sampson, 1923) included extensive coverage of the poisonous range plants. Most of the Agricultural Experiment Stations in the Western Range states published bulletins on poisonous range plants early in the history of these organizations which, as mandated by the Morrill and Hatch Acts, kept a close eye out for practical problems impacting ranchmen and farmers. In the context of this aspect of Range Management it is important that those anticipating careers in or closely related to this field learn the poisonous plants in their area. Producers want names (common ones will suffice), and they have great respect for those who can correctly identify the plants causing the stock poisoning.
The milkweed flowers have a unique structure. The petals of the corolla occur beneath a corona that is comprised of five hoods each typically having a beak or crest. Surrounded by the five-part corona is the actual flower or sex organ portion made up of a five-stamen androecium and the compound pistil or gynoecium which adhere to each other. Together the adnated stamens and pistil form a resultant structure called a gynostegium.
Crowley County, Colorado. July.
Man has proved to be one of the most effective plant dispersal agents. For better or worse (often unintentionally for worse) this includes dispersal of diaspores of plants (including bacteria and fungi in the generic sense of plant) that naturalize to become weeds or pathogenic pests. Under certain cropping systems or in some operations certain of these noxious naturalized plants are of value in production agriculture. This is especially the case for Range Management due to the extensive and often opportunistic nature of this ecological-based husbandry. Two common alien weed species of the Chenopodaceae (goosefoot family) that grow on North American range and fall under a general heading of "usually a weed but often a beneficial plant" were included with Great Plains grasslands.
92. Just too good- Three photographs of broadleaf milkweed in such a classic setting and with such detail (more of God's gifts to this photographer) that they had to be included. The immensely broad, paddle-shaped leaves of A. latifolia were particularily pronounced in these specimens growing on the Llano Estacado (Staked Plains) of the Texas Panhandle. Floral details of the inflorescence were presented in the third of these fortituous shots.
Broadleaf milkweed has one of the higher concentrations of cardenolides--the cardio-toxins found in Asclepias species--of all the milkweeds (Barrow and Tyrl, 2001, p. 133). Milkweed poisoning of animals is intriguing because it has taken place in both birds and mammals, and in ruminants and nonruminants. Some of the earliest studies of stock-poisoning on North American ranges were with the milkweeds.Readers were referred to the detailed description in Burrows and Tyrl (2001, ps. 125-135).
Oldham County, Texas. Mid-July.
93. Almost as wrinkled as its leaves- Follicles, the fruit type of Asclepias species, of broadleaf milkweed. There is much diversity in external features of follicles as in leaves of the various milkweeds. The prominently raised ridges or decidedly rugose surface of leaves and, even more so, of follicles is a readily seen feature of broadleaf milkweed. The follicle is a dry, dehiscent (it opens along one suture) fruit formed from a single carpel, the ovule-bearing structure of the flower (Smith, 1977, ps. 66, 296).
Oldham County, Texas. Mid-July.
A showy one- Showy milkweed (Asclepias speciosa) is a common and widespread milkweed of mixed and shortgrass prairies. A description of the Asclepias species as relevant to Range Management, including poisonous properties, and basic Botany was presented in above captions that introdued the milkweeds in this chapter.Showy milkweed is a strongly rhizomatous species that forms local cononies as seen here.
Yuma County, Colorado; late-June, mid- to full-bloom phenological stage.
Showy details- Top-down view of shoot apex showing leaves and inflorescences (upper or first slide) and details of a single flower cluster or inflorescence (lower or second slide) of showy milkweed. For a description of the Asclepias flower students were once again referred to Smith (1977, 187-188; ).
The milkweeds are common and widespread across the Great Plains. The Great Plains Flora Association (McGregor et al., 1986) described in detail 28 Asclepias for the greater Great Plains region, but this unfortunately left out most of the Great Plains in Texas while encompassing, in other states, areas far to the east of the Great Plains proper. A. speciosa is certainly one of the textbook species of mixed prairie and shortgrass plains grasslands. Showy milkweed prefers comparativelymesic microhabitats.
First slide: Big Horn County, Monatana; mid-June, mid-bloom phenological stage. Second slide: Yuma County, Colorado; late-June, mid-bloom.
94. Russian thistle or tumbleweed, the "tumblin' tumbleweed" (Salsola kali tenuifolia= S. pestifer= S. tragus= S. iberica)- This plant is not, precisely speaking, a thistle nor is it the only tumbleweed, there being several plant species that blow across the land in a rolling motion following breakage of their basal stem. This species is, however, the tumbleweed unless otherwise specified. Russian thistle is the more commonly used name and the preferred common name. The usual story has it that Russian thistle was introduced into South Dakota from Eurasia in contaminated flaxseed and that after a few decades it had thoroughly naturalized across much of the Western Range (Forest Service, 1940, W. 165). This species is indeed a weed in field crop production, but when young and later when dead and dry (and moistened by frost, snow, etc.) Russian thistle is rated as fair or higher in palatability. Perhaps the greatest value of this tumble weed is reduction of soil erosion by its extensive cover on abandoned farmland ("old fields" in the ecological literature; "go-back land" among rangemen, farmers, stockmen), overgrazed ranges, and oil and gas fields. It also provides cover for smaller species of wildlife such as upland game birds.
Russian thistle may at times be toxic due to either oxalates or nitrate accumulation and when dry it can cause slight mechanical injury by its pointed leaves (see next slide), but overall it is a fairly desirable range forb, especially on severely disturbed lands.
Mitchell County, Texas. October; peak standing crop.
95. Leader of Russian thistle- This terminal portion of one branch (there are hundreds per plant) of tumbleweed was included to show the spiny leaves and fruits which are urticles (small fruits with the pericarp free from the single seed; often viewed as a bladdery fruit). This annual species is one of the most prolific plants on Earth. Russian thistle produces thousands of the tiny fruits per plant and when the plant breaks off upon dying and rolls across the land it spreads seeds at a phenomenal rate. Mitchell County, Texas. October.
96. Kochia or summercypress or belvedere (Kochia scoparia)- This is another annual Eurasian chenopod that thoroughly naturalized on the North American Great Plains. Like Russian thistle this development has generally been viewed as somewhat beneficial (perhaps even more so) especially in Range Management, and for the same reasons. The forage value of kochia is good for both livestock and wildlife though it can cause nitate poisoning and other toxicities. The same can be said for most field crops of course. Kochia also provides protection against erosion. Like Russian thistle kochia is a tumbleweed. Shortly after the annual plant dies it breaks near the ground surface and is blown over the land effeciently distributing the gametophytic generation to produce the sporophytic generation in the next growing season. The tumble weeds like kochia and Russian thistle are some of the best examples of wind dispersal (anemochory).
Occasionally kochia has been planted and grown as a forage crop. This was mostly in the Southern High Plains region where kochia was seeded as an annual agronomic crop and managed for high-quality pasture for cattle having high nutrient requirements (eg. developing replacement heifers, lactating beef cows). Sheep and deer also find kochia palatable, often highly palatable at immature phenological stages.As is the case for many otherwise desirable forage species, kochia can be toxic to livestock and wildlife under certain conditions when it accumulates nitrate or by causing secondary (hepatogenic) photosensitization.
The field of kochia shown here was being grown for certified seed to be sold to commercial growers for pasture plantings. Erath County, Texas. May.
97. Branches of kochia- Leaves and inflorescences of Kochia scoparia. Erath County, Texas. May.
98. Shoots of kochia- Two views of kochia showing characteristic leaves, apical buds, and color patterns on stems. Grant County, Washington. June; pre-bloom stage.
99. More on kochia- Branching pattern and leaf detail on Kochia scoparia. The two plants shown here lacked the more common stem stripes of this species. While leaves of some kochia plants turn red with older age the light maroon stripping is more pronounced on younger portions of shoots. Okanogan County, Washington.June; pre-bloom stage.
100. Why kochia is an effective colonizer- Mature fruit on branches of kochia. The fruits of kochia are utricles, a fruit type characterized as an indehiscent, bladderlike structure having one seed which is loosely enclosed within the fruit wall (Smith, 1977, ps. 66, 311). The utricle is a common fruit type in the goosefoot family (Chenopodiaceae). Even though the fruit of kochia is tiny (as shown by these two photographs taken with a mircrolense), the single dark seed inside the utricle is even smaller. Nonetheless, this is a very effective sexual propagule or germule as this exotic and naturalized species grows to relatively large size (especially for an annual forb) on range, field, and fencerow. More importantly in this context is the effeciency with which this opportunistic, weedy plant pioneers freshly denuded land. Abandoned cropland (old fields or go-back land), overgrazed ranges and pastures, even barnyards and seldom-used corrals are ideal habitat for this colonizing species.
Erath County, Texas. October.
101. Smooth yucca or small soapweed (Yucca glauca)- This is the common species of yucca on the central grasslands from the tallgrass and mixed prairies to the western edge of the shortgrass plains. The sweet flowers are a delicacy to cattle, so much so that presence of flower clusters and seed pods are a giveaway that a range was not grazed when the soapweed was in bloom.
Hamilton County, Texas. May.
102. Prickly poppy (Argemone polyanthemos)- This member of the poppy family is one of the more common forbs on the Southern Great Plains. It grows from the Texas Panhandle to northwestern North Dakota and eastward to the Missouri River in Kansas and Nebraska. Prickly poppy is extremely drought-tolerant as evidenced by this prolific growth during spring-summer of 2002 during the most extreme drought yet recorded for Colorado. It's annual (sometimes, biennial) life cycle enables prickly poppy to take advantage of winter and early spring moisture and avoid the hottest part of summer when evapotranspirtion rates are highest and soil moisture is frequently lowest.
Prickly poppy is an ecological invader and high densities of this species indicate disturbances which can include drought, overgrazing, road construction, and abandoned farmland. Lincoln County, Colorado. June.
103. Flowers of prickly poppy- Inflorescences of prickly poppy are attractive as are those of all Argemone species. The genus Argemone should not be confused with the "true poppy" genus, Papaver, which includes most of the ornamental species as well as the opium poppy. Lincoln County, Colorado. June.
104. Innards of prickly poppy flower- Interior of inflorescence of A. polyanthemos showing stamens and stigma of this conspicuous member of the Papaveraceae, poppy family. Morgan County, Colorado. Mid-June (late spring), anthesis.
105. Bush morning glory (Ipomoea leptophylla)- This perennial forb is one of the most characteristic and conspicuous wild flowers of the mixed prairie and shortgrass plains range types. Crowley County, Colorado, July.
106. The large woody roots of bush morning glory profide a textbook example that most biomass of grassland, desert, alpine, and tundra plants is in their root systems. These massive roots store reserves of water and energy (largely as carbohydrates) that enable these marvelously adapted plants to survive bitter winters, prolonged droughts, defoliation, etc. through dormancy and then to initiate new growth (or regrowth) when conditions become favorable. Crowley County, Colorado, July.
107. Raising a stink- Portion of the herbaceous vine (shoot) of stink or buffalo gourd (Cucurbita foetidissima) with an open pistillate flower (left) and an open staminate flower (right).
Erath County, Texas. Mid-May; first open flowers of this growing season.
108. Distaff side of a stink- Side views (first two slides) and inside view (thrid slide) of female flower of stink or buffalo gourd.
Erath County, Texas. Mid-May; first open flowers of this growing season.
109. Mars' spear- Male inflorescence of stink or buffalo guard. This was the flower on the right in the photograph of a section of the viney shoot that introduced this section.
Erath County, Texas. Mid-May; first open flowers of this growing season.
110. Now wave to the folks- Wavyleaf thistle or, sometimes, gray thistle (Cirsium undulatum) growing on blue grama-dominated mixed prairie in the Southern High Plains. Wavyleaf thistle is a widely distributed native perennial or, sometimes, biennial forb. It is not an invasive exotic weed. In fact, at typical densities at which this species grows on climax and high seral stage grasslands it is not a weed at all. Specimens shown here were growing on highway right-of-way beside a blue grama-dominated range in Excellent condtion class, and with even less wavyleaf thistle than on the protected land. Why? Because livestock and wildlife find this a fairly palatable species so that it is often more common where grazing is reduced or unlikely.
Huerfano County, Colorado. Late June (early summer), peak-bloom to early fruit stages.
111. Showy heads on the plains- Heads of wavyleaf thistle on some large select specimens. Typically heads on solitary on each shoot or branch of shoot of the plant. The first plant was blue grama-dominated range on the westernmost edge of the Southern High Plains (Huerfano County, Colorado) while the second plant was growing in a swale of western wheatgrass in the eastern portion of the Southern High Plains (Gray County, Kansas). Late June (early summer), peak-bloom to early fruit stages.
112. No spines here, just sweets- Heads of wavyleaf thistle with pollen-feeding beetles having a heyday. First slide, Gray County, Kansas; second slide, Huerfano County, Colorado. Late June (early summer).
Little 'un thinks he's hid (he ain't)- Head of wavyleaf thistle was a colorful throne for this instar of the plains luber grasshopper (Brachystola magna). This naive junior may not make it to adulthood if he's clueless enough to be sitting out like this (not exactly camouflaged). At least he got in the papers for his few minutes of fame.
Washington County, Colorado. Mid-June.
113. Fixing to fly off- Wavyleaf thistle at peak of ripe fruit production and just before the achenes are shed from the heads. Details of the capitulum at fruit-shatter stage. Examples seen here were growing in a stand of smooth bromegrass. In this instance (and opposite from the typical situation), the thistle was the native.
Thomas County, Kansas. Mid July; ripe fruit phenological stage.
114. Another spiny one on the plains- Yellowspine thistle (Cirsium ochrocentrum) is another perennial or, sometimes, biennial tht is widely distributed on the Great Plains This species resembles rather closely wavyleaf thistle including presence of grey tometose pubescence on undersides of leaves (McGregor et al., 1986, ps. 908-913). Yellowspine and wavyleaf thistles are found on similar habitats. Specimens presented here were growing on a mixed prairie range in Excellent range condition class. Neighboring plant species included blue grama, silver bluestem, sideoats grama, sand dropseed, buffalograss, and western ragweed.
Oldham County, Texas. Mid-July; peak standing crop, full-flower, and fruit-ripe stages of phenology.
115. Sex, anybody?- Flowering capitulum and fruiting heads filled with achenes of yellowspine thistle growing on climax mixed prairie, a cattle range in Excellent range condition class. This plant was growing on th inside (pasture side) of an Excellent condition class cattle range. There can be biological diversity--including often-weedy species--in the climax range vegetation. Case in point shown here (and immediately above).
Oldham County, Texas. Mid-July; peak standing crop, full-flower, and fruit-ripe stages of phenology.
116. Standing baskets on the plains- American basketflower (Centaurea americana) on pristine mixed prairie on a cattle range in the Raton Section of the Great Plains physiographic province. American basketflower is in the thistle tribe, Cynareae, of the Compositae. While many members of the thistle tribe are perennials or biennials American basketflower is an annual. As such there is great year-to-year fluctuation in populations (density and relative abundance) of this species. A combination of various weather conditions came together for a "bumper crop" in a "basketflower year" when these two (and subsequent) photographs were taken.
Oldham County, Texas. Mid-July; peak standing crop and full-flower stages of phenology.
117. Mounted baskets in the Arbuckles- Another sample of a "bumper crop" of the annual thistle, American basketflower. Large populations of Centaurea americana occurred in the same year over a vast geographic region from the tallgrass prairies of Grand Prairie of northcentral Texas up through the tallgrass country of the central and wastern Central Lowlands and across to the mixed prairies of the High Plains and Colorado Piedmont. The examples presented in these two slides were growing in the ancient Arbuckle Mountains of southern Oklahoma. Viewers can readily see the differences in color pattern between capitula (heads) of plants growing on the plains of northwest Texas and those whose home was the "Everlasting Hills of Lklahoma" (Arbuckle Mountain Range).
As is often case of members of the Cynareae (thistle tribe of Compositae), the annual American basketflower prefers disturbed and otherwise more harsh environments. The shallow, stoney soils of an Edgerock range site on which these plants were growing, was a case in point.
Murray County, Oklahoma. Latge May; peak standing crop and full-flower stages of phenology.
118. Details (woven and otherwise) laidout- Various views of capitula (head inflorescences) of American basketflower. Differences in color of heads between the two in the first photograph and the one of third photograph are due to opening of disk flowers, head in third slide had fully opened disk flowers whereas the two heads in the first slide had still unopened disk flowers. The second slide presented ventral (bottom) and lateral (side) views--left and right, respectively--of capitula to show origin of the common name of basketflower. The woven-like arrangement or basket-resembling structures at base of the capitulum are overlapping sissected phyllaries (Diggs et al., 1999, p. 332) which are bracts (modiffied or reduced leaves) below and surrounding the head--specifically, the receptacle--of composites (Smith 1977, p. 304; Diggs et al., 19099, p. 1446).
Arbuckle Mountains, Murray County, Oklahoma. Late May; full-development of capitulum.
119. Broom snakeweed (Gutierrezia sarothrae)- This is one of the dominant half-shrubs of many areas of the Mixed Prairie and Short Grass Plains range types. With regard to woodiness and perennial nature of its shoots it defies ready definition, but perhaps it is best described as suffruticose meaning that it has decidedly woody permanent stems which extend up some distance from ground level but which then remain herbaceous and die at end of each growing season. Broom snakeweed is a native half-shrub that under certain conditions becomes a dreadful weed dominating millions of acres of range even ranges in Excellent condition. Mechanisms that trigger this invasion vary. This pest is not just the result of overgrazing, but it can drastically reduce yields of palatable forage. Then strangely after a number of years (and large sums of money spent on research and control) broom snakeweed disappears as suddenly as it appeared.
The problem (and politics) of broom snakeweed caused a major research effort by the New Mexico Agricultural Experiment Station resulting in many publications. This is an example of the "pracitical education" at our grand land grant universities as established by the Morrill Act of 1862.
Hays County, Nebraska. October.
120. Inflorescences of broom snakeweed- Midland County Texas. October.
121. Just what the grasslands needed: another species of snakeweed (and yellow composite)- Annual or prairie broomweed (G. draculoides). This is one of the most common and widespread composites on both tallgrass and mixed prairies, especially in more southernly locations. The two plants (one entire plant plus half the crown of its range mate) presented here was growing on the Grand Prairie of northcentral Texas, a little bluestem-dominated tallgrass prairie community. Annual broomweed is considerably less widely distributed across the Central Lowlands and Great Plains than is broom snakeweed (McGregor et al.,1977, p. 373), but its species range is more than large enough for rangemen preferring grass over annual, weedy composites. Annual broomweed has a far-flung distribution across Texas which has some of the greatest remaining acreage of mixed prairie range, albeit mostly in Poor and Fair range condition classes.
Annual or prairie broomweed is an early seral stage colonizer (sometimes a pioneer species) of abused land (eg. overgrazed ranges and those recovering from recent drought, go-back land, highway rights-of-way). Thus this annual broomweed is both an indicator plant as well as a protective (as against soil erosion) and facilitative species that enhances plant succession.
Erath County, Texas. October; full-bloom stage.
122. More yeller flowers- Closer-in views revealed an "ocean" of yellow flowers in part of one annual broomweed. Multiply this fraction of one plant times millions of other plants and it takes no imagination to understand why abused ranges--including those just recovering from extreme drought--look more like rape and canola fields than prairies.
G. draculoides is in the Astereae (aster tribe) of the Compositae.
Erath County, Texas. October; peak-bloom stage.
123. Ragged denizen of the western (and also of the eastern, northern, and southern) ranges-- Colony of western ragweed (Ambrosia psilostachya) in the Raton Section of the Great Plains physiographic province. This extremely hardy and highly rhizomatous perennial composite (tribe, Heliantheae) is so extraordinarily adapted to the North America that its biological range extends from Nova Scotia to British Columbia and south to Florida missing only a few states along the Atlantic shore and part of the Appalachian Mountain chain. Western ragweed is one of the most consistently found of all plants on the diverse range types of North America.
Quay County, New Mexico. Late July; peak standing crop and full-flower stages of phenology.
124. Ragged westerner (also easterner, northerner, and southerner)- Overall view of shoot (first photograph) and upper sexual shoots with inflorescences (second photograph) of western ragweed. Ambrosia species are monecious with staminate flowers above pistillate flowers these latter of which are borne in axils of upper leaves. Flowers of both sexes are interpreted as heads (capitula) so that Ambrosia species are included in the huge tribe, Heliantheae. The entire inflorescence of western ragweed is a a spike-like affair (second slide).
Quay County, New Mexico. Late July; peak standing crop and full-flower stages of phenology.
125. Berlandier's beauty- Lyreleaf chocolate flower or lyreleaf greeneyes
(Berlandiera lyrata) growing on a silver bluestem-sideoats grama
mixed prairie range. Berlandiera, one of the smaller genera of
the Helianthese (one of the largest of the Compositae tribes), was named
after J.L. Berlandier who was a Euopean physican and amateur naturalist
and anthropologist who collected plants in Texas and northern Mexico.
He later became a member of the International Boundary Commission that
established the international border between Republic Mexico and the
United States of America.
B. lyrata is one of three Berlandiera species in Texas where it typically maintains some green growth throughout most of the year (Correll and Johnston, 1979, p. 1624), an uncommon growth feature among herbaceous species.
There were two plants in this photograph.s
Howard County, Texas. Mid-October; peak-bloom stage.
126. Floral features- Heads and maturing disks of achenes of lyreleaf greeneyes or lyreleaf chocolate flower. These examples were on the plant on the right in the preceding photograph. Howard County, Texas. Mid-October; peak-bloom stage.
127. Big for its age- A specimen of annual or common sunflower (Helianthus annuus) at peak-bloom stage (first slide) and a characteristic shoot with typical leaves of annual sunflower (second slide) on the Raton Section of the Great Plains physiographic province. The author has seen naturally growing plants of common sunflower on native Great Plains grasslands that exceeded 11 to almost, 12 feet in height. There is considerable genetic (genotypic and ecotypic) vriation in H. annuus. Add to this phenotypic plasticity and there is often great differences in habit of this forb.
Quay County, New Mexico. Late July; peak standing crop and full-flower stages of phenology.
128. Foliaceous views- Topdown view of shoot (first slide) and details of shoot surface or epidermis and leaf axil (second slide) of annual or common sunflower. Although common sunflower is a large, rank-growing, weed-like forb it is generally quite palatable to larger herbivores such as cattle. The specimens of comon sunflower presented in these and the immediately preceding and succeeding sets were growing on the right of way of a major interstate highway (I 40). In ranges grazed by cattle and/or sheep that adjoined Interstate 40 (the pasture or enclosed side of the interstate highway fence) there were no such sunflowers. This de facto controlled experiment showed unequivocally the palatability of Helianthus annuus to livestock.
Quay County, New Mexico. Late July; peak standing crop and full-flower stages of phenology.
129. A moment in the sun- Front (first slide) and back (second slide) sides of the capitulum (head inflorescence) of common or annual sunflower. The anther-eating coleopteran in the first photograph was an orange blister beetle (Nemognatha lurida). Perhaps this visitor (an unwelcome guest perhaps) was the one who had also eaten parts of petals of ray flowers.
Quay County, New Mexico. Late July; peak standing crop and full-flower stages of phenology.
130. A common and very important forb- Whether viewed from perspectives of popular culture as the State Flower of Kansas (or the National Flowre of Ukraine) or of commerce as one of the world's major oilseeds annual sunflower (Helianthus annuus) is an important plant. As a native range plant, common or annual sunflower is one of the most widely distributed of all the prairie forbs. The natural biological range os helianthus annuus clearly included most of the whole of the Americas. The original species range of common sunflower would be impossible to determine given that the species unquestionably has expanded its current biological range following its human-assisted expansion, first, as a common weed and, second, as domesticated field crop. Both extremes are a classic example of adaptation to--perhaps some degree of co-evolution with--man the farmer. Annual sunflower was domesticated by American Indians in Mesoamerica (along with so many other major crop species). The current range of annual or common sunflower is planet-wide or global.
Across ther ranges of North America common sunflower is frequently abundant on all the central grasslands from tallgrass to semidesert grassland. Annual sunflower is "at home" in all North American deserts where it sometimes attains heights of over six feet. In North America common sunflower grows as far north as the Northwest Territories of Canada. Common sunflower does have one stipulation: it does not tolerate shade. Even with that habitat limitation annual sunflower often thrives in forest communities following denudation due to clearcutting, forest fires, wind or ice storms, and disease outbreaks. It is, of course, on the great grasslands where common sunflower is so "common" (sorry about that). This robust annual is particularily abundant on tallgrass, true, and mixed prairies.
Common sunflower is currently used for bioremiadition, specifically phytoremediation, as well as a field crop where uses range from oilseed to bird feed to biodiesel. A good reference for this is the agronomic monograph edited by There is no equivalent treatment for H. annuus as a native plant, but all the floras (manuals) and "wild flower" field guides covered it. It seemed strange to this author that common sunflower was not included in the Phillips Petroleum series, Pasture and Range Plants nor was this species on the Society for Range Management "200 List" (the Master Plant List for the International Range Plant Identifiction Contest) or in the accompanying volume, North American Rnage Plants (yet the SRM included common dandelion [Taraxacum officinale]). In fact, there is not one Helianthus species on the SRM Plant Identification List (Stubbendieck et al., 1992). Damned dandelion and no sunflower? I'd be for changing that situation, pronto!
Hatch and Pluhar (1993) did include Helianthus maximilliani in Texas Range Plants, but still no H. annuus. Leave it to the sod-busting "dirt farmers" to get one up on the rangemen. Grazing animals, including grass-preferring cattle, readily eat annual sunflower. Based on this rangeman's observations, cattle find the leaves of common sunflower particularily palatable.
Common sunflower, as befits annuals, is a colonizer or pioneer species. Some might snort "weed", but this applied ecologists would quickly (and correctly) point out that under secondary plant succession the processes of colonization or, the complete phase, invasion is an essential part of natural revegetation. In such cases, common sunflower is no more a weed than it is when used as an oil cropof phytoremiator. Common sunflower is part of the "crop" in early seral stages of natural revegetation through "old field" succession. Jayhawkers got it right;: annual sunflower was a fitting choice for state flower of a prairie state.
There is tremendous diversity (in size and shape of plants as well as in leaf, stem, and flower features) in H. annuus. "This is a huge, polymorphic complex encompassing numerous wild and weedy races, plus the tall, strict, large-headed cultivated phases" (Great Plains Flora Association, 1986, p. 954).
Bank of Colorado River, Runnels County, Texas. Mid-October; full-bloom to early fruit stage.
131. Composite- The flower cluster or pattern of flower arrangement as a whole of the Compositae (sunflower or aster family) is a composite affair, the inflorescence type being a head or capitulum. Smith (1977, ps. 63, 291) described the capitulum as "a dense spherical or rounded inflorescence of sessile [unpediceled] flowers" or "an aggregation of + sessile flowers on a common receptacle". More specifically in case of the Compositae the head consist of numerous small flowers (florets) seated within a common receptacle or disk that is conical, hemispheric or flattened in general shapewith this entire unit encircled gy an invloucre of braxcts termed phyllaries.Phyllaries are arranged in one or more series or in overlapping fashion. The actual flowers of composites (as all members of the Compositae are known) can be of one or two types: 1) disk or tubular flowers which are inserted in the disk (ie. the central part of the inflorescence) and 2) ray or ligulate flowers which surround or encircle the disk and are inserted around the perimeter of the common receptacle. Generally, inflorescences of the Compositae can be of both tubular (disk) and ligulate (ray) flowers or only ray (tubular) flowers. Ray flowers can be of two types. This confusing composite situation was explained by Smith (1977, ps. 214-217).
In tribe Heliantheae (of which Helianthus species are members) capitula can be composed of either: 1) tubular along with one type of ligular (disk) flowers or 2) strictly tubular (ray) flowers. Helianthus species have only one series of ray (ligulate) florets which are pistillate but infertile (yellow in color) while the disk (tubular) florets are prfect and fertile (hence the only source of fruit). In H. annuus these disk florets vary from shades of red to purple to, sometimes, yellow (Great Plains Flora Association, 1986, p.s 953, 954). The fruit of Helianthus species is an achene (a dry, indehiscent, single-seeded fruit).
Bank of Colorado River, Runnels County, Texas. Mid-October; full-bloom to early fruit stage.
132. Various stages- Heads of common sunflower in various phenological stages. In the first slide flower-fruit (maturity) stages were full-bloom, early fruit filling, and fruit shatter stages right to left and front to rear. In the second slide the head at peak flowering stage was to right and front of a head at fruit-shedding stage. This complete array of head maturation was perhaps attributable to recent recovery of sunflower plants after heavy rains broke a summer-long Exceptional Drought (Palmer Drought Severity Scale rating of D4). Native range plants are survivors.
Bank of Colorado River, Runnels County, Texas. Mid-October; full-bloom to early fruit stage.
133. A purty one that sprang back- Cusp gayfeather or narrowleaf blazingstar (Liatris mucronata= L. punctata var. mucronata) growing on the Texas Rolling Red Plains shortly after heavy autumn rains followed a summer-long Exceptional Drought (worst one-year drought in Texas history). On this mixed prairie neighboring grass species including silver bluestem, hairy grama, and purple threeawn had either died, or more likely, gone into drought dormacy.
Narrowleaf gayfeather is one of only two Liatris species native to the Rolling Red Plains, out of twelve Liatris species statewide (Gould, 1962). The other species indigenous to the Texas Rolling Red Plains is L. punctata. These two species are weakly separated from each other by a globose corm in L. mucronata versus an elongated, thickened taproot in L. punctata (Great Plains Flora Association 1986, ps. 972-973). In Botany of Western Texas (Colter 1891-1894, p. 182) recognized only L. punctata describing taxon mucronata as a variety of L. punctata distinguishable by "smaller heads and flowers".
The local assemblage seen here undoubtedly consisted of several different (= genetically distinct) plants. Achenes had not drifted too far from their source.
Liatris species have traditionally been interpreted as increasers or even decreasers. In writing this caption the author found Soil Conservice Service soil surveys from Texas, Florida, North Dakota, and to Minnensota that listed various Liatris species (including dotted gayfeather) listed as decreasers. Plants used as examples in this and immediately succeeding slides were on highway right of way whereas there were no gayfeather plants in an adjacent cattle range less than a hundred feet away.
The sensational beauty of these range forbs was all the more remarkable (and enjoyable) when it was appreciated that these plants had produced such blazonry and brought such gaiety to heart following months of scourching heat and rainless skies.
Runnels County, Texas. Mid-October; peak bloom.
134. A blazing victory over drought- Sexual shoots of cusp blazingstar, cusp gayfeather, or narrowleaf gayfeather on highway right of way in the Rolling Red Plains following recent ground-soaking rains that broke an Exceptional Drought (Palmer Severity Index rating of D4), the worst one-year drought in Texas weather records. It can be seen from these slides that "narrowleaf" is an apt adjective for this species; however the very similar dotted gayfeather also has narrow leaves that cannot be distinguished from those of narrowleaf gayfeather. It was explained immediately above that Coulter (1891-1894, p. 182) interpreted the taxon mucrata as a smaller-headed variety of L. punctata. By the way, Coulter (1891-1894) specified that the genus Liatris as having plants that were "often resinous-dotted herbs". In other words, "dotted" as used in dotted gayfeather is not exclusive to any one Liatris species.
Runnels County, Texas. Mid-October; peak bloom.
135. Yes, these are heads- Heads (=capitula) of narrowleaf blazingstar or narrowleaf gayfeather. These inflorescences were on plants presented in the immediately preceding slides. All flowers of Liatris species are tubular or disk flowers (ie. there are no ligulate or ray flowers). Th head or capitulum inflorescence type (a composite head) was described above under the second caption for common sunflower.
Runnels County, Texas. Mid-October; peak bloom.
136. Small flower; large plant- Flowering shoots (first slide) and shoot bases (second slide) of small-flower, lizard-tail, velvet-leaf, or velvety gaura (Gaura parviflora= G. mollis) growing in a dense local stand on mixed prairie in the Southern Great Plains. This member of the Onagraceae, evening primrose family, is an annual (sometimes starting growth in winter), rank-growing (commonly regarded as "weedy"), tall (some shoots seen approached ten feet in height) prairie forb that is well-adapted to disturbed areas. Small-flower gaura, which occurs as both individual plants and local stands (like the one shown here), is one of the largest of all the native forbs found on tallgrass and mixed prairies.Small-flower gaura is a good example of an r-selected species like other tall-growing, rank annuals such as annual sunflower and giant ragweed (Ambrosia trifida). These large annual forb species are adapted to disturbance (colonizing degraded habitats) with high resource allocation to shoots rather than roots and to sexual rather than asexual reeproduction
Small-flower gaura does grow large taproots (Diggs et al., 1999, p. 856). Haddock (2005, p. 108) noted that Indians sometimes eat the big roots. .The author could not find reference to consumption of this forb by wildlife or livestock nor had he ever seen evidence of use by range animals. Conversely, one almost never sees these "big weeds" on livestock ranges other than that are lightly grazed. This suggests that some grazing animals make use of these plants for forage.
Good botanical descriptions of small-flower gaura were provided in McGregor (1986, p. 511) .
Quay County, New Mexico. Late July; early flower development stage.
137. "Rank-growing" is the operative description- Example of the large stem and stem-clasping leaves of velvety or small-flower gaura in the Southern Great Plains. This shoot was on one of the plants in the stand shown in the immediately preceding two slides.The base of some of the larger shoots in this stand were as big as a man's big toe.
Quay County, New Mexico. Late July; full-grown shoot stage.
Velvet leaf- Leaf and axillary area of velvet-leaf, velvety, lizard-tail, or small-flower gaura growing in the West Cross Timbers in northcentral Texas. That this member of the primrose family (Onagraceae) is widely distributed and well-adapted to subhumid and semiarid grasslands and savannahs was attested to by the fact that this example of a leaf and some views of flowers shown below grew in the more mesic and eastern part of its species range.
Velvet-leaf gaura has a vast species range that extends across much of North America from New England across the Upper Midwest to Idaho and Washington and south to Arizona and northern Mexico, including Dorango and Sonora (Fernald, 1950, p. 1070; Correll and Johnson, 1979, p.1124). Across this immense land space, small-flower gaura does best (and is typically found growing on xeric habitats (dry, disturbed ground such as roadsides, railroad rights-of-way, field edges, etc.).
Lizard-tail or small-flower gaura is an annual and it has the large organs (including leaf, stem, and taproot) typical of rank-growing annual forbs. Velvet-leaf gaura clearly has the morphological features of a classic r-selected plant species (Barbour et al.,1999, ps. 109-111).
Erath County, Texas. Early May; peak standing crop.
138. Small flowers on a not-so-small inflorescence- Upper portion of sexual shoot (first slide), flower cluster (second slide), and several individual flowers (third slide) of small-flower gaura in a mixed prairie in the Southern Great Plains. This inflorescence was one of many in the local stand of lizard-tail or small-flower gaura shown immediately above. Inflorescence type of lizard-tail gaura is a spicate raceme (Diggs et al, 1999, p. 855).
Quay County, New Mexico. Late July; early flower development stage.
More views of a botanical lizard-tail- Two progressively closer camera-views of inflorescence and flowers on lizard-tail, velvet-leaf, velvety, or small-flower gaura growing in the West Cross Timbers of northcentral Texas. This annual forb is opportunistic with regard to flowering. In northcentral Texas the flowering period of small-flower gaura extends from April through October (Diggs et al., 1999, p. 856) which encompasses most of the frost-free period of this area. A relatively high allocation of the plant's resources to sexual reproduction, and this over an extended period of time are features of r-selected species (Barbour et al.,1999, ps. 109-111).
Erath County, Texas. Early May; peak standing crop, peak-bloom phenological stage.
139. One for the unwashed masses- Threadpetal blazing star or threadpetal stickleaf (Mentzelia strictissima) growing on a moist microsite in Southern Mixed Prairie in northeastern New Mexico. In this area, the western and northern boundary of the Southern High Plains or Llano Estacado (Staked Plains) merges almost imperceptively with the adjoining edges of the Colorado Piedmont and Raton Section, all divisions or sections of the Great Plains physiographic province (Fenneman, 1931, ps. 11-17, 30-40; Trimble, 1980). A rich flora and diverse grassland vegetation exist is the meeting or overlapping place on the plains.
Threadpetal blazing star is an extremely conspicuous member of this diverse range plant community. Actually there are at least eight Mentzelia species in New Mexico alone.(Ivey, 2003, ps. 317-319). Mentzelia are in the stickleaf family (Loasaceae) which is a tiny family compared to a lot of the relatively small range forb families no t to mention the gaint forb families like sunflower family (Compositae) and legume family (Leguminosae). The Mentzelia species "make up for" their small number of taxa by having some of the most ornate, elegant, and eye-catcching flower clusters of the range vegetation to which they belong.
Even the most crass and craziest of interstate motorists (and a high proportion of this them fit into this vulgar collective) cannot fail to glimpse these spectacular flowers, which in instance of M. strictissima, are produced on large herbaceous shoots. General or relative size of the threadpetal stickleaf plants seen here can be guaged by comparing them to their botanical neighbors (which they overtopped), sand sagebrush (Artemisia filifolia).
Quay County, New Mexico. Mid-July; peak-bloom phenological stage.
140. Visual sensation; practical nusiance- Current season's (year's) flowering shoots and last year's stalk of capsules (first slide) and example of inflorescences and leaves (second slide) of threadpetal stickleaf on a moist microhabitat in the southwestern Great Plains. This local area had received abundant rains (while most adjoining areas were in Extreme Drought) and range plants responded accordingly.
It was explained immediately above and below that the silvery, cream-colored flower clusters of this large-growing species show up sensationally even to speeding drivers. Noone would deny that these are spectacular and "fair to behold" trees in the Garden of Eden (Genesis 3:6) Abraham's wife, Sarah, "fair to behold" To woolgrowers these sensationally flowered range plants are a pain in their docks as the coarse pubescence of these species results in parts of leaves and stems sticking to the fleece (Kearney and Peebles, 1960, p. 564) and frequently causing dockage in wool prices (Diggs et al., 1999, p. 796). Small (1933, p. 897) noted that this pubescence was effective in cutting the legs off of small insects unfortunate enough to light on them. McGregor et al. (1986, p.270) listed three kinds of hairs on Mentzelia plants: "spinelike, glochidiate, and harpoon-topped". This "stickery" feature of Mentzelia species is basis of the common name, stickleaf (Kearney and Peebles, 196o. p. 564; Diggs et al, 1999, p. 796).
Perennial Mentzelia species are "mostly suffrutescent herbs" (McGregor et al. (1986, p. 270).
Quay County, New Mexico. Mid-July; peak-bloom phenological stage.
141. Gits even their attention- Flower clusters of threadpetal stickleaf on a moist microsite in the Southern Great Plains.Kearney and Peebles (1960, p. 564) described Mentezelia species as being "handsome in flower". The author saw these beautiful forbs from an interstate highway and remarked above that even speeding (speed limit-exceeding) motorists (likely eight nine out of ten) would be hard put to miss these showy beauties (not that they would care).
All of the floras cited above noted the adhering-to-hair feature of Mentzelia leaves and stems (hence, stickleaf). This undesirable feature from an animal standpoint and the likely lack of palatability of these species to grazing animals renders this range forb a pest (noxious range plant), curosity, and eye-catching member of the range plant community. The role(s)--if any--of threadleaf stickleaf to neighboring plants which ranged from sand sagebrush to sand bluestem (Andropogon hallii) was unknown. This does not mean that this species was/is a weed (other than in context highlighted above). It might well have a valuable role in the mixed prairie range ecosystem of which it was one of the most conspicuous members.
Quay County, New Mexico. Mid-July; peak-bloom phenological stage.
142. Unsensational fruit of a visually sensational forb- Last year's sexual shoot with fruit (capsules) shells on threadleaf stickleaf on a Southern Great Plains mixed prairie range.
Quay County, New Mexico. Mid-July; dead, a spent force (except for remaining viable seeds which are never to be ignored).
143. Another sticky plainsman- Adonis, manyflowered, or prairie stickleaf (Mentzelia multiflora) on a mixed prairie range in the Southern Great Plains. This second Mentzelia species was also growing in the area where the Staked Plains (Llano Estacado), Colorado Piedmont and Raton Section of the Great Plains physiographic province all converged. Plants of this stickleaf species are considerably smaller and much less showy than threadleaf stickleaf detailed immediately above, but they still have the "messy" feature of sticking to pelage (including that of human-fashioning).
This plant of manyflowered stickleaf was growing on a climax (Excellent range condition class) mixed prairie cattle range dominated by blue grama and with sideoats grama and silver bluestem as associates plus sand dropseed, broadleaf milkweed, American basketflower, and walkingstick cholla this latter of which giving a savanna physiogonomy to a beautiful grassland. A few widely scattered plants of manyflowered stickleaf added still more botanical biodiversity to a textbook example of Southern Mixed Prairie. (Note: that textbook example was featured in the chapter, Mixed Prairie- IA of Range Types; the plant species just listed--several of them on this same Excellent condition class range--were presented earlier in this chapter.)
Spidderish or beeish on the Central Plains- Rocky Mountain bee plant or spider flower (Cleolme serrulata) on mixed prairie on the Central Great Plains. This annual forb of the caper family (Capparaceae) ismost common on disturbed sites such as on the ranch road side seen here. On such damaged areas or local microhabitats, Rocky Mountain spider plant can be found in large populations. Presence of large numbers of Rocky Mountain bee plant is--as with most annuals on graslands--indicative of abuse (at least at local scale). Is biological diversity due to plants like (versus, say, nothing but grama grasses and buffalograss) a good thing?
It is a strikingly attractive native range plant. Rocky Mountain spider plant is sometimes used by native plant enthusiasts for prairie-scaping and in flower beds of native species. Honey bees (various races of Apis mellifera) are happy to see flowers of this caper, but there again these hard-working little hymenopterans are domesticated species and far from native to North America.
Pawnee National Grassland, Weld County, Colorado.Mid-June.
Got your eye, hugh?- The Rocky Mountain bee plant or spider flower (or, sometimes, spider plant) has a showy inflorescence which, together with the drooping capsules (its fruit type), gives the common name referring to to spider. Yes, bees (and other flower-feeeding insects) are attracted to its flowers. Capsules are borne on long, thin stalks that are gynophores Great Plains Flora Association, 1986, ps. 291-292). Gynophore refers to the stalk or stem inside a flower on which the gynoecium (i.e pistil) is held (Smith, 1977, p. 297).
This whole arrangement of inflorescence and capsule-bearing structures is (with some imagination) suggestive of a large spider, hence spider flower or spider plant.
Pawnee National Grassland, Weld County, Colorado. Mid-June.
144. Canadian or russet buffaloberry (Shepherdia canadensis)- Buffaloberry is one of the more common shrubs in the grasslands of the Northern Great Plains and Columbia Plateau (especially the Interior Northwest portion between the Cascade Range and the nortrern ranges of the Rocky Mountains).It often grows in more protected areas like coulees. Buffaloberry is usually poor to worthless (rarely fair) as browse, but the fruit is valuable in diets of birds. Cardston Municipal District, Alberta. July.
1456. Wood wild rose (Rosa woodsii)- Enjoy the famed wild rose of Alberta. The wood rose is one of relatively few shrubs in the mixed prairie of the northern Colorado Plateau and the rough fescue grassland. This slide showed details of leaves and of inflorescences. This view presented to the student the structure known as the hypanthium: the greater sexual part of a flower in which a shallow cup-like structure (sometimes an elongated tube) formed by fusion of the perianth (calex and corolla collectively) and the androecium (stamens collectively) which surrounds the gynoecium (carpels collectively; female part of flower, pistil in older terminology). Cardston Municipal District, Alberta. July.
146. Shoot tip of wood wild rose- Here is another detailed view of the famed wild rose of Alberta showing the ripening structures known as "hips". The hip is the tough, round-shaped structure that is surrounding the actual fruits of the rose which are achenes. An achene is a dry, one-seeded indehiscent fruit with pericarp and seed coat separate except where joined at the funiculus. The achenes which at first seem to be "seeds" are inside the hip which at first-flush appears to be the fruit. The hip is not the actual fruit because the seeds are inside the achenes-- making them the fruits-- which are arranged inside the hip. Hips are thus characterized as "false fruits".
Rose hips are often valuable feed for range animals because they contain high concentrations of nutrients. There are numerous Rosa species in North America, including naturalized ornamentals which became noxious pests. Dayton (1931, ps. 46-49) estimated that there were about 55 Rosa species native to "the Western States". He described 16 species of wild rose. The Range Plant Handbook (Forest Service, 1940, B135) described 11 Rosa species. Most of the wild roses provide browse ranked by Forest Service investigators as fair to excellent. Some species, in particular the spineless ones, are subject to severe overuse and eventual overbrowsing. Some wild roses are riparian species and valuable for protection of watersheds and aquatic environments (eg. as regards fish habitat).
Cardston Municipal District, Alberta. July.
147. Four-wing saltbush (Atriplex canescens)- This member of the Chenopodiaceae is a valuable and widely distributed browse plant that was a dominant shrub of such diverse range types as mixed prairie and plains and mesa grasslands, Chihuhuan and Great Basin Deserts. As seen here is a dioecious species (a male plant at left and female plant at right). Weld County, Colorado. August.
148. Winter-fat (Eurotia lanta)- This chenopodacious browse plant furnishes critical winter feed to all species of range ungulates, including horses (Sampson and Jesperson, 1963; Stubbendieck et al., 1992). Otero County, Colorado, July.
149. Plains pricklypear (Opuntia polyacantha)- This is the most common cactus on the vast grasslands of the Great Plains. Its range extends from the Chihuhuan Desert north and west to the plains grasslands of Alberta to rank as one of the northernmost cactus species in North America (Benson, 1982, ps.111, 382-393). University of Lethbridge, Alberta.
150. Sprawlin' in the shortgrass- Plains pricklypear on a locally disturbed microsite on mixed prairie in the Piedmont Plains to the west of the Southern High Plains and east of the Front Range in southeast Colorado. This cactus was growing on a grassland of blue grama, buffalograss, sand dropseed, western wheatgrass, cheatgrass, and silver bluestem. This area was undergoing a relative severe drought and most of the perennial grasses were dormant except for a few stolons on buffalograss and isolated tillers of blue grama. Even plants of plains pricklypear were conspicuously drought-stressed (see next slide).
Las Animas County, Colorado. Late June.
151. Shriveled but still sexy- Two consectuively closer views of parts of the plains pricklypear introduced in the preceding photograph. The first of these two slides featured the extremely shriveled condition of cladophylls (the padlike shoots) of this cactus. This "wrinkled" appearance was due to water loss from the typically succulent, water-storing shoots, one of the most important water-conserving, survival adaptations of this xerophytic species. The extreme condition of water-depravation in this plant was striking.
In spite of this extreme state of water-stress the plains prickly was blooming. It was persistently carrying out sexual reproduction and exchanging gametes to propagate the genes, the funadmental cellular unit of natural selection. Details of sexual reproduction were preented in the second photograph. A ripening berry (the fruit of cactus) produced in the previous year was to the immediate of the newly opened cactus flower (ie. two years and two phenological stages of sexual reproduction were shown in this slide).
Las Animas County, Colorado. Late June.
152. Sex in two kingdoms- Two newly opened flowers on the plant of plains pricklypear that was introduced two captions above. This tough little xerophyte on a mixed prairie range was performing sexual reproduction even under drought-caused water stress so severe that cactus cladophylls were shriveled from water loss As if not to be outdone, two hymenopterans (of a species unknown to this author) were also engaged in sexual reproduction adorned in the simple beauty of a cactus flower. Both plant and animal species were "dutifully" passing on the genes of their respective races to their posterity and to the preservation of biodiversity, structure, and function of this range ecosystem.
Could there be anything in creation that bespeaks better the meaning of life? The Creator Himself must surely have paused to marvel and smile approval on one of the routine miracles in His creation. It also seemed likely that if Charles Darwin had passsed this way he would have penned a note of the survival fitness of these two manifestations of natural selection. Another brief episode on the great grasslands of the continental interior.
Las Animas County, Colorado. Late June.
So purty we had to have anothern- Another flower of plains pricklyper and with a host of insects. Showy flowers with rich stores of nectar are relatively rare on the mixed prairie so insects "come a'flying, a'crawling, or however they can git there" to what few flowers there are.
Pawnee National Grassland, Weld County, Colorado.Mid-June.
Anothercolor on the plains- Plains pricklypear also has a unique red color--regarded as magenta-, pink-, or rose-colored--among its flowers. These rose-toned flowers are not common so when a photographer finds one it is worth sharing. This coloration does not distinguish different taxa within O. polycantha. Great Plains Flora Association (1986) recognized two taxonomic varieties of O. polycantha based on rigidity of spines on areoles.
Pawnee National Grassland, Weld County, Colorado.Mid-June.
Another color shade- Flowers of plains pricklypear with the uncommon rose-, pink-, or magenta color.
Pawnee National Grassland, Weld County, Colorado.Mid-June.
153. Walkingstick cholla (Opuntia imbricata)- This is but one of many species of Opuntia. It is widely distributed across the grasslands of the Great Plains where its aspect dominance gives a savanna-like appearance to a sea of short- and midgrasses. It is an example of a succulent and woody wild flower. The cholla group of Opuntia is in subgenus Cylindropuntia.
Guadalupe County, New Mexico, July.
154. Phenological progression in walkingstick cholla- Two floral buds nearly ready to open (first photograph) and two flowers at full bloom on the same plant (second photograph). Nolan County, Texas. May.
155. Shootfire, fruits on cholla shoots- The fruit of walkingstick cholla is borne at apex of the fleshy, cylindrical stems of this common (often defining) shrub on the Southern High Plains (Llano Estacado, meaning Staked Plains). In this species of Opuntia the cactus fruits occur in small groups (clusters) in contrast to singularly along shoot tips in pricklypear.
Noland County, Texas. March.
156. A single cholla fruit- One fruit of cholla cactus removed to present details. The cactus fruit is interpreted as a many-seeded berry (Smith, 1977, p. 104). The fruit of walkingstick cholla is armed with short spines and glochids, but these are punty affairs as compared for example to those of many of the pricklypears.
Noland County, Texas. March.
157. Contents of cholla fruit- A fruit of cholla catcus cut open revealing seeds. First photograph was interior of fruit immediately after being cut open (note thichness of the fleshy portion of fruit wall and moist membrane around seeds). Second photograph was interior of fruit 24 hours after cutting open (note shrinkage of fleshy portion of fruit wall and dried membrane surrounding seeds as compared with appearance immedately following opening as shown in first photograph).
Noland County, Texas. March.
158. It'll will reach out and grab ya- Typical plant of catclaw or catclaw acacia (Acacia greggii var. greggii). This acacia species is widely distributed growing from northern Mexico to the Pacific Ocean (coastal northern California) and in three North Amcerican deserts (Mojave, Sonoran, and Chihuhuan). It also calls the Rolling Red Plains of Texas home which is where the following examples were photographed.
Runnels County, Texas. Mid-October; ripe-fruit stage.
159. Little enough but present- Small catkin and compound leaf of catclaw acacia produced on the Rolling Red Plains of Texas. It was expolained in the immdediately preceding caption that catclaw is a widespred--and thus morphologically vriable--woody legume. Catclaw acacia sometimes blooms profusely with large, fully filled inflorescences. The example seen here was produced in the single worst one-year drought in texas weather records.So this plant did well to produce even this much.
Runnels County, Texas. Mid-October; early stage of flowering in this catkin.
160. Legume and leaves- Examples of legumes and small compound leaves of catclaw acacia produced on the Rolling Red Plains of Texas in the worst single-year droughton record. Catclaw is more abundant on a regional basis in the Rio Grande Plains than in the Rolling Plains portion of the Great Plains. This species is also widespread in the Chihuhuan, Sonoran, and Mojave Deserts.
Runnels County, Texas. Mid-October; ripe-fruit stage.
161. Ready to grow- Ripe, dehisced legume with seeds of catclaw acacia. Runnels County, Texas. Mid-October; following an Exceptional Drought.
Location note: tree species of Great Plains mixed prairie grasslands were included with the other various chapters of Mixed Prairie and/or Tallgrass Prairie.
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