Elymus virginicus
Elymus riparius
common eastern wild-rye, Virginia wild rye, élyme de virginie
eastern riverbank wild-rye, river wild-rye, riverbank wildrye, élyme des rivages
30-130 cm, erect to slightly decumbent;
nodes 4-9, concealed or exposed, usually glabrous, rarely pubescent.
70-160 cm, erect, sometimes rooting at the lower nodes;
nodes 5-10, mostly concealed, glabrous.
evenly distributed;
sheaths usually glabrous, rarely hirsute, occasionally reddish or purplish;
auricles absent or to 1.8 mm, pale brown;
ligules shorter than 1 mm;
blades 2-14(18) mm wide, usually spreading or lax, sometimes becoming involute, basal blades similar to the upper blades, adaxial surfaces usually smooth, sometimes scabridulous, usually glabrous, occasionally pubescent.
evenly distributed;
sheaths usually glabrous or scabridulous, often reddish brown;
auricles absent or to 2 mm, brown;
ligules shorter than 1 mm;
blades (5)8-15(25) mm wide, flat, lax, dull green, drying to grayish, adaxial surfaces glabrous or scabrous.
(3)4-16(22) cm long, 1-2.2(2.5) cm wide, erect, the bases often sheathed, with 2 spikelets per node, rarely with 3 at some nodes;
internodes 3-5 mm long, 0.25-0.5 thick at the thinnest sections, smooth and glabrous, or scabrous, or with hairs beneath the spikelets.
7-25 cm long, 2-4 cm wide, nodding, exserted, usually with 2 spikelets per node, rarely with 3 at some nodes;
internodes 3-5(8) mm long, 0.2-0.35 thick at the thinnest sections, usually glabrous below the spikelets.
10-15 mm, appressed to slightly divergent, with (2)3-4(6) florets, lowest florets functional;
disarticulation below the glumes and each floret, or the lowest floret falling with the glumes.
10-20 mm, strongly divergent, with 2-3(4) florets, lowest florets functional;
disarticulation above the glumes and beneath each floret.
subequal or equal, the basal 1-4 mm terete, indurate, without evident venation, bowed out, yellowish, glume bodies 7-15 mm long, (0.5)0.7-2.3 mm wide, linear-lanceolate, widening above the base, 3-5(8)-veined, usually smooth or scabridulous, margins firm, awns 3-10(15) mm, straight;
lemmas 6-10 mm, scabridulous, glabrous or villous-hirsute, awns (5)8-20(25) mm, straight;
paleas 5-9 mm, obtuse;
anthers 2-3.5(4) mm.
equal or subequal, 14-30 mm including the sometimes undifferentiated awn, the basal 0.5-2 mm terete, indurate, straight or nearly so, veins not evident, glume bodies 9-17 mm long, (0.3)0.5-0.8(1) mm wide, linear-setiform, entire, widening or parallel-sided above the base, 2-3(4)-veined, usually hispidulous or scabrous, rarely glabrous, margins firm, awns (5)8-18 mm, straight;
lemmas 7-14 mm, usually hispidulous, sometimes scabrous, awns 15-35 mm, usually straight, those of the basal spikelets occasionally contorted;
paleas 6-9 mm, usually acute, sometimes obtuse to truncate, bidentate;
anthers 2-2.7 mm.
usually mid-June to late July (mid-August).
late June to late July.
= 28.
= 28.
Elymus virginicus
Elymus riparius
Elymus virginicus is widespread in temperate North America, growing as far west as British Columbia and Arizona. It is infrequent to rare in the Rocky Mountains, western Great Plains, and southeastern coastal plain. It is a complex species, divided here into four intergrading varieties.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus riparius grows in moist, usually alluvial and often sandy soils in woods and thickets, usually along larger streams and occasionally along upland ditches. It is widespread in most of temperate east-central North America. It is rare in southern Ontario and Quebec, and the eastern Great Plains. It is virtually absent from the southeastern coastal plain.
Elymus riparius is relatively uniform and distinct. It is sometimes confused with E. canadensis (see next), but that species has curving awns. It hybridizes occasionally with several other taxa, especially E. virginicus var. virginicus (p. 300) and E. hystrix (p. 316), but the hybrids produce only late, depauperate spikes or none at all (e.g., Church 1958).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Spikelets hispidulous to villous-hirsute, usually glaucous; anthesis usually in early July to mid-August | var. intermedius |
1. Spikelets usually glabrous or scabrous, glaucous or not; anthesis usually in mid-June to late July. | → 2 |
2. Spikes partly sheathed; glumes 1-2.3 mm wide, strongly indurate and bowed out in the basal 2-4 mm; plants not glaucous, becoming yellowish brown or occasionally somewhat purplish at maturity | var. virginicus |
2. Spikes exserted; glumes (0.5)0.7-1.5(1.8) mm wide, moderately indurate and bowed out in the basal 1-2 mm; plants usually glaucous, becoming yellowish or reddish brown at maturity. | → 3 |
3. Culms usually 70-100 cm tall, with 6-8 nodes; blades 3-15 mm wide, flat; spikes 4-20 cm long, not strongly glaucous; glumes indurate only in the basal 1 mm | var. jejunus |
3. Culms usually 30-80 cm tall, with 4-6 nodes; blades 2-9 mm wide, often becoming involute; spikes 3.5-11 cm long, often strongly glaucous; glumes usually indurate in the basal 1-2 mm | balophilus |
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