Elymus curvatus |
Elymus albicans |
|
---|---|---|
awnless wild-rye, awnless wlldrye, beardless wild rye |
Montana wheatgrass, Montana wild rye |
|
Habit | Plants cespitose, not rhizomatous, often glaucous. | Plants strongly rhizomatous. |
Culms | 60-110 cm, stiffly erect, or the base sometimes geniculate; nodes 6-9, concealed or exposed, glabrous. |
40-100 cm, erect or decumbent only at the base, glabrous. |
Leaves | evenly distributed; sheaths glabrous, often reddish brown; auricles to 1 mm, sometimes absent; ligules shorter than 1 mm, ciliolate; blades 5-15 mm wide, the lower blades usually lax, shorter, narrower, and senescing earlier, the upper blades usually ascending and somewhat involute, adaxial surfaces smooth or scabridulous, occasionally scabrous. |
somewhat basally concentrated; sheaths glabrous; auricles usually present, to 0.8 mm; ligules 0.2-0.5 mm, ciliolate; blades 1-3 mm wide, usually involute, adaxial surfaces scabrous to strigose. |
Spikes | 9-15 cm long, (0.5)0.7-1.3 cm wide, erect, exserted or the bases slightly sheathed, with 2 spikelets per node; internodes 2.5-4.5 mm long, about 0.25-5 mm thick at the thinnest sections, smooth or scabrous beneath the spikelets. |
4-14 cm long, 1.5-2.5 cm wide including the awns, 0.3-0.8 cm wide excluding the awns, erect, with 1 spikelet per node; internodes 6-14 mm long, 0.2-0.4 mm wide, glabrous or pubescent beneath the spikelets. |
Spikelets | 10-15 mm, appressed, often reddish brown at maturity, with (2)3-4(5) florets, lowest florets functional; disarticulation below the glumes and beneath the florets, or the lowest floret falling with the glumes. |
10-18 mm, 1.5-2 times longer than the internodes, appressed to ascending, with 3-7 florets; rachillas strigillose; disarticulation above the glumes, beneath each floret. |
Glumes | equal or subequal, the basal 2-3 mm terete, indurate, strongly bowed out, without evident venation, glume bodies 7-15 mm long, 1.2-2.1 mm wide, linear-lanceolate, widening above the base, 3-5-veined, usually glabrous or scabrous, occasionally hispidulous, rarely hirsute on the veins, margins firm, awns 0-3(5) mm; lemmas 6-10 mm, glabrous or scabrous, rarely hirsute, awns (0.5)1-3(4) mm, rarely 5-10 mm on the lemmas of the distal spikelets, straight; paleas 6-10 mm, obtuse, often emarginate; anthers 1.5-3 mm. |
subequal, 1/2 as long as to almost equaling the adjacent lemmas, glabrous or hairy, weakly keeled, keels and adjacent veins smooth to evenly and strongly scabrous from the base to the apices, margins 0.2-0.3 mm wide, apices acute, acuminate, or shortly awned; lower glumes 4-8 mm; upper glumes 4.5-8 mm; lemmas 7.5-9.5 mm, glabrous or densely hairy, awns 4-12 mm, at least some strongly divergent; paleas subequal to the lemmas, tapering to the 0.1-0.3 mm wide apices; anthers 3-5 mm. |
Anthesis | late June to mid-August. |
|
2n | = 28, 42. |
= 28. |
Elymus curvatus |
Elymus albicans |
|
Distribution |
CO; ID; MT; ND; NE; SD; UT; WA; WY; AB; BC; ON; SK |
|
Discussion | Elymus curvatus grows in moist or damp soils of open forests, thickets, grasslands, ditches, and disturbed ground, especially on bottomland. It is widespread from British Columbia and Washington, through the Intermountain region and northern Rockies, to the northern Great Plains. It is infrequent or rare in the midwest, the Great Lakes region, and the northeast, and is virtually unknown in the southeast. It is similar to E. virginicus (p. 298), and has sometimes been included in that species as E. virginicus var. submuticus Hook., but is more distinct than the varieties of E. virginicus treated above. Although E. virginicus and E. curvatus overlap greatly in range, E. curvatus usually has a distinct growth form, and its anthesis is 1-2 weeks later (Brooks 1974). Its spikes range from being completely exserted, especially west of the Great Plains, to largely sheathed, especially east of the Mississippi River and in more stressed environments. This geographic trend parallels that within E. virginicus, but sheathed plants of E. curvatus can usually be distinguished by their short awns. Clear transitions to E. virginicus, usually var. jejunus, are rare, but, especially from Missouri to Wisconsin, there are occasional plants with 5-10 mm awns on a few lemmas, especially at the spike tips. Rarely, plants from Missouri and Iowa to Quebec have hispid to hirsute spikelets, suggesting introgression with E. virginicus var. intermedius. There are a few records of apparent hybrids with other species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Elymus albicans grows primarily in the central Rocky Mountains and the western portion of the Great Plains. It tends to grow in shallow, rocky soils on wooded or sagebrush-covered slopes, rather than in deep loams. It is derived from hybrids between Pseudoroegneria spicata (p. 281) and E. lanceolatus (p. 327). In practice, it is probably restricted to hybrids involving the awned variant of Pseudoroegneria spicata, because the hybrid origin of those involving the unawned variant would probably not be recognized. Populations of Elymus albicans differ in their reproductive abilities (Dewey 1970). In some, most plants yield good seed; in others, most plants are sterile. Some fertile populations appear to be self-perpetuating; others appear to consist of recent hybrids and some backcrosses. Although treated here as a species, E. albicans could equally well be treated as a hybrid in xPseudelymus (p. 282), but the combination has not been published. Plants with glabrous lemmas, presumed to be derived from crosses with glabrous individuals of E. lanceolatus, have sometimes been treated as a distinct taxon, e.g., Agropyron albicans var. griffithsii (Scribn. 8c J.G. Sm.) Beetle or A. griffithsii Scribn. & J.G. Sm.; they are not formally recognized here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 300. | FNA vol. 24, p. 334. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Triticeae > Elymus | Poaceae > subfam. Pooideae > tribe Triticeae > Elymus |
Sibling taxa | ||
Synonyms | E. virginicus var. submuticus, E. virginicus var. jenkinsii, E. submuticus | E. albicans var. griffithsii, Agropyrum griffithsii, Agropyron albicans var. griffithsii, Agropyron albicans |
Name authority | Piper | (Scribn. &c J.G. Sm.) Á. Löve |
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