Elymus wiegandii
Elymus villosus
northern riverbank wildrye, Wiegand's wild-rye, élyme de Wiegand
downy wild-rye, hairy wildrye, silky wild rye
100-180(220) cm, erect;
nodes 9-16, mostly concealed by the leaf sheaths, glabrous.
40-130 cm, erect;
nodes 4-8, concealed or exposed, glabrous.
evenly distributed;
sheaths usually glabrous, occasionally villous, often reddish brown;
auricles 1-3 mm, brown;
ligules to 1 mm;
blades (8)10-20(24) mm wide, flat, lax, dark green, adaxial surfaces usually thinly pilose, with weakly spreading hairs on the veins at least near the margins, sometimes villous or glabrous.
evenly distributed;
sheaths villous-hirsute, pilose, or occasionally glabrate, occasionally reddish brown;
auricles 1-3 mm, brownish;
ligules shorter than 1 mm, entire or erose;
blades 4-12 mm wide, lax, dark glossy green, adaxial surfaces usually densely velutinous-villous with fine whitish hairs, rarely pilose only on the veins.
10-30 cm long, 3-5 cm wide, pendent, the bases often barely exserted, with 2 spikelets per node;
internodes 5-8(12) mm long, 0.2-0.3 mm thick at the thinnest sections, usually pubescent beneath the spikelets.
4-12 cm long, 1.5-3.5 cm wide, slightly or strongly nodding, exserted, usually with 2 spikelets per node, rarely with 1 or 3 at a few nodes;
internodes (1.5)2-3(4) mm long, 0.15-0.25 mm thick at the thinnest sections, usually hairy below the spikelets, rarely glabrous.
12-20 mm, divergent, with (3)4-6(7) florets, lowest florets functional;
disarticulation above the glumes and beneath each floret.
7-12 mm, moderately divergent, with 1-2(3) florets, lowest florets functional;
disarticulation above the glumes and beneath each floret.
equal or subequal, 12-30 mm including the often undifferentiated awns, the basal 0.5-1 mm subterete and slightly indurate, glume bodies 7-12 mm long, (0.2)0.4-0.9(1.1) mm wide, linear-setiform, entire, widening or parallel-sided above the base, 1-3(5)-veined, glabrous, hispidulous or villous, especially near the margins, margins firm, awns (5)8-15(18) mm, straight or flexuous;
lemmas 10-15 mm, usually uniformly appressed-villous, rarely scabrous-hirtellous or glabrous, awns 15-25(30) mm, moderately to strongly outcurving;
paleas 9-14 mm, narrowly truncate, minutely bidentate;
anthers 2-3.5 mm.
equal, 12-25 mm including the often undifferentiated awns, the basal 0.5-2 mm terete, slightly indurate, straight or nearly so, without evident venation, glume bodies 7-10 mm long, (0.2)0.3-0.8 mm wide, linear-setiform, widening or parallel-sided above the base, 2-3(4)-veined, usually hirsute to hispid, occasionally scabrous to scabridulous, margins firm, awns 5-15 mm, straight;
lemmas 5.5-9 mm, usually villous with fine, whitish, spreading hairs, especially near the margins and apices, sometimes glabrous or with coarser hairs, sometimes scabrous, awns 9-33 mm, straight;
paleas 5-7.5 mm, obtuse, occasionally emarginate;
anthers (1.6)2-3(4) mm.
from mid-July to early August.
early June to early July.
= 28.
= 28.
Elymus wiegandii
Elymus villosus
Elymus wiegandii grows in moist or damp, rich, alluvial soil, especially on sandy river terraces and in woods and thickets, primarily from Saskatchewan through much of the Great Lakes region to Nova Scotia and Connecticut. It has abnormal neocentric chromosomes with meiotic irregularities that appear to limit the fertility of its hybrids, and even some crosses within the species (Vilkomerson 1950). It may be derived from hybrids between E. canadensis (p. 303) and perhaps E. riparius (p. 302). The latter species is similar to E. wiegandii and overlaps with it in range and habitat within the Great Lakes region, where there are a few plants that appear to be hybrids between the two. Plants with scabrous-hirtellous or glabrous lemmas (E. wiegandii f. calvescens Fernald) are known from Maine and New Hampshire.
Elymus wiegandii is often confused with sympatric E. canadensis and E. diversiglumis (p. 316), but it has a distinctive robust, broad-leaved habit. It is intermediate between the two in spike density and glume development. Occasional plants with glabrous leaves and less pendent spikes suggest introgression from E. canadensis, but artificial crosses produced no fertile Fj plants (Church 1958).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus villosus grows in moist to moderately dry, often rocky soils in woods and thickets, especially in calcareous or other base-rich soils, but it is also frequent on drier, sandy soils or damper, alluvial soils in glaciated regions. It extends from the Great Plains east to southern Quebec, northern New York, and Vermont south to Texas, Georgia, and South Carolina. It is absent from the southern portion of the coastal plain.
Elymus villosus is relatively uniform and distinct, although it has sometimes been confused with hairy plants of E. canadensis (p. 303) and E. glabriflorus (p. 296). The hairs of E. villosus are fine, whitish, and consistently dense on the leaf blades, typically spreading in the spikelets; the hairs of the other species are typically stouter and more appressed in the spikelets. Plants called E. villosus var. arkansanas (Scribn. & C.R. Ball) J.J.N. Campb. are scabrous to glabrous in the spikes, except for the ciliate rachis margins, and often more robust. These are scattered over much of the species' range, except in the north (from Wisconsin to New England), and are locally more frequent than typical plants in the Ozark Mountains and other midwestern hills. Some other western plants (including those called E. striatus var. ballii Pammel) have unusually large, almost erect spikes, suggesting introgression from E. virginicus (p. 298). There are rare apparent hybrids with species in the E. virginicus group, but the only proven natural hybrid is with Hordeum fubatum (p. 245) (see *Elyhordeum, p. 283). Artificial crosses with several species failed to produce healthy Fj plants (Church 1958).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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