Elymus macgregorii
Elymus canadensis
early wild-rye
Canada wild rye, Canadian wild rye, Great Plains wild-rye, élyme du Canada
40-120 cm, erect or slightly decumbent;
nodes 4-8, mostly exposed, glabrous.
(40)60-150(180) cm, erect or decumbent;
nodes 4-10, mostly concealed by the leaf sheaths, glabrous.
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 smooth or scabridulous, glabrous or hirsute, often reddish brown;
auricles 1.5-4 mm, brown or purplish black;
ligules to 1(2) mm, truncate, ciliolate;
blades (3)4-15(20) mm wide, usually firm, often ascending and somewhat involute, usually dull green, drying to grayish, adaxial surfaces usually smooth or scabridulous and glabrous, rarely sparsely hispid to 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.
6-30 cm long, 3-7 cm wide, usually nodding, sometimes pendent or almost erect, usually with 2(3) spikelets per node, occasionally to 5 at some nodes, rarely with 1 at some nodes but never throughout;
internodes (2)3-5(7) mm long, or 5-10 mm long towards the base, 0.2-0.35 mm thick at the thinnest sections, glabrous or with a few hairs below 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.
12-20 mm excluding the awns, more or less divergent, with (2)3-5(7) florets, lowest florets functional;
disarticulation usually above the glumes and beneath each floret, rarely also below the glumes.
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.
usually equal, occasionally subequal, 11-40 mm including the awns, the basal 0-1 mm subterete and slightly indurate, glume bodies 6-13 mm long, 0.5-1.6 mm wide, linear-lanceolate to subsetaceous, entire, widening or parallel-sided above the base, 3-5-veined, glabrous to scabrous-ciliate, rarely villous on the veins, margins firm, awns (5)10-25(27) mm, straight to outcurving;
lemmas 8-15 mm, glabrous, scabrous, hispid, or uniformly villous with the hairs generally appressed, awns (10)15-40(50) mm, moderately to strongly outcurving, often contorted at the spike bases;
paleas 7-13 mm, acute, usually bidentate;
anthers 2-3.5 mm.
usually mid-May to mid-June.
May to July.
= 28.
= 28, rarely 42.
Elymus macgregorii
Elymus canadensis
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 canadensis grows on dry to moist or damp, often sandy or gravelly soil on prairies, dunes, stream banks, ditches, roadsides, and disturbed ground, or, especially to the south, in thickets and open woods near streams. It is widespread in most of temperate North America, extending from the southwestern Northwest Territories to Coahuila, Mexico, being especially common in the Great Plains. Reports from California and the southeastern states appear to be based on misidentifications. E. canadensis is considered a good forage species.
Elymus canadensis is sometimes confused with E. riparius (see previous), from which it differs in having curved rather than straight awns; and with E. wiegandii (p. 305), from which it differs in its less robust habit and narrower leaves. It can hybridize with E. glabriflorus (p. 296), E. virginicus (p. 298), E. hystrix (p. 316) and allies, E. glaucus (p. 306), E. trachycaulus (p. 321), Pseudoroegneria spicata (p. 281), and other species. Subsequent introgression may have contributed to much of the diversity within the genus (Pohl 1959; Brown and Pratt 1960; Nelson and Tyrl 1978; Davies 1980; Campbell 2002). The three varieties recognized here show clear differences in their typical expression and evidence some geographic separation, but they may prove to be artificial reference points within a more or less continuous variation (Sanders et al. 1979). Nevertheless, crossing barriers sometimes exist between the varieties, and even between some sympatric strains (Church 1954, 1958, 1967a).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lemmas usually villous or hispid; spikes nodding to almost pendent; internodes 4-7 mm long, often strongly glaucous | var. canadensis |
1. Lemmas usually smooth or scabridulous, occasionally hirsute; spikes usually nodding, occasionally almost erect; internodes 3-4 mm long, not strongly glaucous. | → 2 |
2. Glumes not clearly indurate or bowed out at the base, awns 10-20 mm long; lemmas smooth or scabridulous, awns usually 20-30 mm long, moderately outcurving; spikes 6-20 cm long | var. brachystachys |
2. Glumes often slightly indurate and bowed out at the base, awns 15-25 mm long; lemmas occasionally hirsute, awns 30-40 mm long, often strongly outcurving; spikes 15-25(30) cm long | var. robustus |
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