Elymus macgregorii
Elymus elymoides
early wild-rye
bottlebrush, bottlebrush squirreltail, long-bristle wildrye, squirrel tail grass, squirreltail, western bottle-brush grass
40-120 cm, erect or slightly decumbent;
nodes 4-8, mostly exposed, glabrous.
8-65 (77) cm, erect or geniculate to slightly decumbent, sometimes puberulent;
nodes 4-6, mostly concealed, usually glabrous, sometimes pubescent.
evenly distributed;
sheaths usually glabrous, rarely villous;
auricles 2-3 mm, usually purplish black when fresh, sometimes light brown;
ligules shorter than 1 mm;
blades 7-15 mm wide, lax, dark glossy green under the glaucous bloom, adaxial surfaces usually glabrous, occasionally villous.
evenly distributed;
sheaths glabrous, scabrous, puberulent, or densely white-villous;
auricles usually present, to about 1 mm, often purplish;
ligules shorter than 1 mm, truncate, entire or lacerate;
blades (1)2-4(6) mm wide, spreading or ascending, often involute, sometimes folded, abaxial surfaces glabrous to puberulent, adaxial surfaces scabrous, puberulent, hirsute, or white-villous.
4-12 cm long, (1.7)2.2-3(4)4 cm wide, erect, exserted, with (6)9-16(20) nodes and 2 spikelets at all or most nodes, sometimes with 3 at some nodes;
internodes 4-7 mm long, about 0.3 mm thick and 2-angled at the thinnest sections, usually glabrous or scabridulous beneath the spikelets.
3-20 cm long, 5-15 cm wide, erect to sub-flexuous, with 2-3 spikelets per node, rarely with 1 at some nodes;
internodes 3-10(15) mm long, 0.1-0.4 mm thick at the thinnest sections, usually glabrous, sometimes puberulent beneath the spikelets.
10-15 mm, strongly divergent, glaucous, maturing to pale yellowish brown, with (2)3-4 florets, lowest florets functional;
disarticulation below the glumes and each floret, the lowest floret often falling with the glumes.
10-20 mm, divergent, sometimes glaucous, at least 1 spikelet at a node with 2-4(5) florets, 1-4(5) florets fertile, sometimes all florets sterile in the lateral spikelets;
disarticulation initially at the rachis nodes, subsequently beneath each floret.
subequal, entire, the basal 1-3 mm terete or subterete, indurate, without evident venation, moderately bowed out, glume bodies 8-16 mm long, 1-1.8 mm wide, linear-lanceolate, widening or parallel-sided above the base, (2)4-5(8)-veined, usually glabrous, occasionally hirsute, sometimes scabrous, margins firm, awns (10)15-20(25) mm, straight except the awns of the lowest spikelets occasionally contorted;
lemmas 6-12 mm, usually glabrous, sometimes scabrous, occasionally villous, awns (15)20-30 mm, straight;
paleas 6-10 mm, apices obtuse;
anthers 2-4 mm.
subequal, 20-135 mm including the often undifferentiated awns, the bases indurate and glabrous, glume bodies 5-10 mm long, 1-3 mm wide, linear to setaceous, 1-3-veined, margins firm, awns 15-125 mm, scabrous, sometimes split into 2-3 unequal divisions, flexuous to outcurving from near the base at maturity;
fertile lemmas 6-12 mm, glabrous, scabrous, or appressed-pubescent, 2 lateral veins extending into bristles to 10 mm, awns 15-120 mm long, about 0.4 mm wide at the base, often reddish or purplish, scabrous, flexuous to curved near the base;
paleas 6-11 mm, veins often extending into bristles to 2(5) mm, apices acute to truncate;
anthers 0.9-2.2 mm.
usually mid-May to mid-June.
from late May to July.
= 28.
= 28.
Elymus macgregorii
Elymus elymoides
Elymus macgregorii grows in moist, deep, alluvial or residual, calcareous or other base-rich soils in woods and thickets, mostly east of the 100th Meridian in the contiguous United States. It used to be confused with E. glabriflorus (p. 296) or E. virginicus (p. 298), but it reaches anthesis about a month earlier than sympatric populations of these species. In most of its range, E. macgregorii has purplish black auricles; light brown auricles may be locally abundant, particularly in populations at the limits of its range.
Elymus macregorii hybridizes with several species, but especially E. virginicus and E. hystrix (p. 316) (Campbell 2000). Western plants often have smaller, more condensed spikes and distinctly villous leaves, suggesting a transition to E. virginicus var. jejunus (p. 300). Transitions to E. virginicus var. jejunus can also be recognized to the north, where the dates of anthesis are delayed, but even in Maine, E. macgregorii reaches anthesis about 10 days earlier than E. virginicus (Campbell and Haines 2002). Plants with villous lemmas grow at scattered locations; they have not been reported in distinct habitats, nor in large enough populations to warrant taxonomic recognition.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus elymoides grows in dry, often rocky, open woods, thickets, grasslands, and disturbed areas, from sagebrush deserts to alpine tundra. It is widespread in western North America, from British Columbia to northern Mexico and the western Great Plains, and introduced in western Missouri, Illinois, and Kentucky. It is often dominant in overgrazed pinyon-juniper woodlands. Although palatable early in the season, the disarticulating, long-awned spikes irritate grazing animals later in the year.
Elymus elymoides intergrades with E. multisetus (see previous) in parts of its southern range (Wilson 1963). It is sometimes confused with E. scribneri (p. 330), but differs in having more than one spikelet per node, narrower glumes, and less tardily disarticulating rachises. Hybrids with several other species in the Triticeae are known; they can often be recognized by their tardily disarticulating rachises. Named interspecific hybrids (pp. 338-343) (and the other parent) are E. xsaundersii (E. trachycaulus), E. xpinalenoensis (E. arizonicus), and possibly E. xhansenii (E. elymoides or E. multisetus x E. glaucus). Hybrids with E. sierrae have not been named; they are common where the two species are sympatric. They have broader glume bases, shorter glume awns, and longer anthers than E. elymoides.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Rachis nodes with 3 spikelets, the central spikelet usually with 2 fertile florets, the florets of the lateral spikelets rudimentary to awnlike; lemma awns 15-30 mm long | subsp. hordeoides |
1. Rachis nodes usually with 2 spikelets, each spikelet usually with (1)2-4(5) fertile florets; lemma awns 15-120 mm long. | → 2 |
2. No spikelets appearing to have 3 glumes, the lowermost floret in each spikelet well developed; paleas rarely with the veins extended as bristles | subsp. brevifolius |
2. One or more of the spikelets at most nodes appearing to have 3 glumes, the lowest 1-2 florets sterile and glumelike; paleas usually with the veins extended as bristles. | → 3 |
3. Glumes with awns 15-70 mm long, all glumes entire | subsp. californicus |
3. Glumes with awns 35-85 mm long, one of the glumes at most nodes with the awn split into 2 or 3 divisions | subsp. elymoides |
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