Elymus hystrix
Elymus canadensis
bottlebrush grass, eastern bottle-brush grass, glumeless wlldrye
Canada wild rye, Canadian wild rye, Great Plains wild-rye, élyme du Canada
50-140 cm, usually erect, occasionally geniculate below;
nodes 4-8, exposed or concealed, glabrous.
(40)60-150(180) cm, erect or decumbent;
nodes 4-10, mostly concealed by the leaf sheaths, glabrous.
evenly distributed;
sheaths usually glabrous, occasionally pilose, often purplish;
auricles usually present, 0.5-3 mm, brown to black;
ligules 1-2(3) mm;
blades 4-16 mm wide, lax, usually deep glossy green, adaxial surfaces pilose or scabridulous.
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.
7-20 cm long, 4-7 cm wide, more or less erect, usually with 2 spikelets per node, rarely with 3 at some nodes;
internodes (3)4-8(10) mm long, (0.1)0.2-0.3(0.4) mm thick at the thinnest sections, flexuous, usually glabrous, sometimes scabrous or hirsute, usually with green lateral bands.
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.
10-18 mm, strongly divergent to patent at maturity, with (1)2-4(6) florets, lowest florets functional;
disarticulation above the glumes, beneath each floret.
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.
usually vestigial, sometimes 1-3 mm long, about 0.1 mm wide, subulate, entire, with no evident veins, occasionally to 10(20) mm long including the undifferentiated awns and differing in length by more than 5 mm, 0.1-0.2 mm wide, setaceous, tapering from the base, usually glabrous, occasionally appressed-puberulent to strigose, sometimes scabrous, usually straight, rarely somewhat curving, margins firm;
lemmas 8-11 mm, usually glabrous, occasionally appressed-puberulent to strigose, especially near the margins and apices, awns (12)20-40(47) mm, usually straight, rarely somewhat curving;
paleas 7-11 mm, obtuse or truncate, occasionally emarginate;
anthers 2.5-5 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.
mid-June to early July.
May to July.
= 28.
= 28, rarely 42.
Elymus hystrix
Elymus canadensis
Elymus hystrix grows in dry to moist soils in open woods and thickets, especially on base-rich slopes and small stream terraces. It grows throughout most of temperate eastern North America, extending west to Manitoba and Oklahoma, but is absent from the southern portion of the coastal plain.
Plants with pubescent lemmas have been recognized as Elymus hystrix var. bigelovianus (Fernald) Bowden. These occur infrequently north of a line from South Dakota through Kentucky to New Jersey, and are often mixed with the typical variety; uniform populations are known in the northeastern United States. Plants with pubescent blades are also more prevalent to the north. Elymus hystrix hybridizes with most eastern species of Elymus. Introgression may account for the considerable variation in glume development and spikelet appression among these species. Lack of glumes may be a recessive character, with even slight glume development indicating introgression (Church 1967b). Plants with relatively well-developed, subequal glumes are presumed to be of hybrid origin. Such plants include most material from the Carolina piedmont region, where E. glabriflorus (p. 296) is the most likely source of introgression. The relatively frequent hybrids with E. virginicus (p. 298) are usually sterile, but Church (1967b) made crosses through three segregating generations. Within the ranges of E. diversiglumis (p. 316), E. svensonii (p. 314), and E. churchii (p. 314;, there appear to be frequent introgressants between these species and E. hystrix. Further east, especially in the Appalachian regions of North Carolina, Virginia, West Virginia, and Maryland (including the shale barrens and nearby), there are scattered plants of E. hystrix with curving awns and, in a few cases, appressed spikelets (Campbell 2002). Whether these represent occasional variation within the E. hystrix gene pool, or whether they are outlying remnants of introgression with E. canadensis (p. 303) during a past eastward extension, is unknown.
(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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