Elymus multisetus
Elymus riparius
big squirreltail, big squirreltail grass
eastern riverbank wild-rye, river wild-rye, riverbank wildrye, élyme des rivages
15-65 cm, erect to ascending, usually puberulent;
nodes 4-6, mostly concealed, glabrous.
70-160 cm, erect, sometimes rooting at the lower nodes;
nodes 5-10, mostly concealed, glabrous.
evenly distributed;
sheaths glabrous or white-villous;
auricles usually present, 0.5-1.5 mm;
ligules to 1 mm, truncate, entire or lacerate;
blades 1.5-4(5) mm wide, often ascending and involute, adaxial surfaces scabrous, pilose, or villous.
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.
5-20 cm long, 5-15 cm wide, erect, sometimes partially enclosed at the base, with 2 spikelets per node, rarely with 3-4 at some nodes;
internodes 3-5(8) mm long, 0.1-0.3 mm thick at the thinnest sections, glabrous 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, divergent, with 2-4 florets, lowest florets sterile and glumelike in 1 or both spikelets at each node;
disarticulation initially at the rachis nodes, subsequently beneath each floret.
10-20 mm, strongly divergent, with 2-3(4) florets, lowest florets functional;
disarticulation above the glumes and beneath each floret.
subequal, (10)30-100 mm including the awns, the bases indurate and glabrous, glume bodies (2)5-10 mm long, 1-2 mm wide, setaceous, 2-3-veined, margins firm, awns (8)25-90 mm, each split into 3-9 unequal divisions, scabrous, flexuous to outcurving from near the glume bases at maturity;
fertile lemmas 8-10 mm, smooth or scabrous near the apices, 2 lateral veins extending into bristles to 10 mm, awns (10)20-110 mm long, about 0.2 mm wide at the base, divergent to arcuate;
paleas 7-9 mm, veins usually extending into about 1 mm bristles, apices acute to truncate;
anthers 1-2 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.
from late May to June.
late June to late July.
= 28.
= 28.
Elymus multisetus
Elymus riparius
Elymus multisetus grows in dry, often rocky, open woods and thickets on slopes and plains, from central Washington and Idaho to southern California, Colorado, and northwestern Arizona, and from sea level to 2000 m. It has also been reported from Baja California, Mexico. It usually grows in less arid habitats than E. elymoides subsp. elymoides (p. 319), but the two taxa are sometimes sympatric.
Wilson (1963) reported a wide belt of introgression between Elymus multisetus and E. elymoides subsp. elymoides from southeastern California to southern Nevada, but not in other areas where they are sympatric. There are also probable hybrids with E. glaucus (p. 306) and Pseudoroegneria spicata (p. 281).
(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.)
- Local floras:
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
Go Botany
IL Wildflowers
MD Biodiversity
MI Flora
MN Wildflowers
MO Plants
