Shortgrass Prairie

5. Shortgrass plains- This was an example of the shortgrass phase or shortgrass community form of mixed prairie. Blue grama and buffalograss were the two dominants of this climax grassland, but western wheatgrass, sideoats grama, and sand dropseed (the classic mid-grasses) were also common while silver bluestem formed distinct colonies (eg. the light tan area in left mid-ground) and individual plants of the cespitose little bluestem were also present. Dominant forb was wild alfalfa. This combination of sod-forming grasses and bunchgrasses is characteristic of mixed prairie, but the predominant sod-grasses were responsible for the shortgrass physiogonomy of this Southern High Plains grassland. The community more typical of mixed prairie (more species-rich) was featured in the foreground to show the biological diversity of plains grassland, but the less diverse blue grama-buffalograss community of the background was the more common community on this cattle range.

Commanche National Grassland, Baca County, Colorado. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K- 61 (Wheatgrass-Grama-Buffalograss) in foreground; K-58 (Grama-Buffalograss) in background. SRM 715 (Grama-Buffalograss). Hardland range site. Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

6. High Plains grassland- This was another example of the shortgrass physiogonomy form of mixed prairie. Blue grama, buffalograss, and galleta (in that order) were dominant species though mid-grass species were common (western wheatgrss, sideoats grama, sand dropseed, and Indian ricegrass were well-represented while prairie junegrass was present but infrequent in this sward). Common plains yucca or soapweed yucca was present as the major forb, but it was more conspicuous than it was common. Widely scattered (barely present) shrubs were cholla and four-wing saltbush.

Crowley County, Colorado. July. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K- 58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss). Loamy Plains range site. Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

7. Shortgrass plains- This landscape was included to show viewers the classic blue grama-buffalograss community interpreted by many prairiemen as a shortgrass disclimax (a grazing or zootic disturbance climax). Beginning range students are referred to Weaver and Albertson (1954, ps. 19-25). The two shortgrass species "have a monopoly" on the plant-growing resources of this ecosystem. As with the grassland communities seen in preceding slides such species as western wheatgrass, sideoats grama, and galleta were also present. Threeawns (Aristida species) were very rare while shrubs and even forbs were non-existant for all practical purposes. Textbook example of shortgrass plains grassland.

From the collection of examples presented here the most ardent plainsmen and fans of the "shortgrass country" can understand why plains-weary travelers (and some "foreigners" not so travel-weary) find this landscape so monotonous and boring. To the true plainsman, however, it is "God's Country" and the finest place on Earth.

Elbert County, Colorado. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss). Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

10. 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.

11. 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.

Tarleton State University College Farm, Erath County, Texas. September, late summer.

15. 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.

16. "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.

17. 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.

18. 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.

19. 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.

21. 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.

23. 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.

24. 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.

27. 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.

28. 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.

30. 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.

31. 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.

32. 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

34. 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.

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.

38. 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.

39. 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.

41. A widespread and prickly character- A specimen of plains pricklypear (Opuntia polycantha) growing in the sward presented in preceding photographs of mixed (mostly mid- and shortgrass species) prairie grassland on the Staked Plains. This cactus grows throughout almost the entire latitudinal extent of the Great Plains from the southern most part of the Llano Estacado to the Canadian Prairie Provinces.

Plains pricklypear is of such short stature that all but the shortest grass species (eg. buffalograss) overtop it. As such almost any fire regard less of intensity, rate of spread, etc. will kill high proportions of this cactus.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October.

44. 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.

45. 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.

46. 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.