Elymus multisetus
Elymus macrourus
big squirreltail, big squirreltail grass
northern wheatgrass, tuft wheatgrass
15-65 cm, erect to ascending, usually puberulent;
nodes 4-6, mostly concealed, glabrous.
35-100 cm, ascending to erect;
nodes sometimes pubescent.
glabrous;
auricles absent;
ligules 0.5-1 mm, truncate to rounded;
blades 3-10 mm wide, flat, usually glabrous, abaxial surfaces smooth or scabridulous, adaxial surfaces scabrous.
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.
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.
5-20 cm long, 0.4-0.8 cm wide, erect, with 1 spikelet per node;
internodes 7-8 mm long, about 0.5 mm wide, 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.
12-20 mm, appressed, with 4-7 florets;
rachillas hairy, hairs 0.3-0.5 mm;
disarticulation above the glumes, 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.
6-10 mm long, 1/3-2/3 the length of the spikelets and to about 1/2 the length of the adjacent lemmas, 0.8-1.8 mm wide, widest at about midlength, lanceolate, flat, rounded, or symmetrically keeled, usually green or green tinged with purple, 3-4-veined, veins scabridulous, scabrous, or with hairs to 0.3 mm, usually glabrous elsewhere, margins subequal, about 0.3 mm wide, widest near midlength, apices acute, unawned or awned, awns to 1 mm;
lemmas 8-12 mm, hairy throughout or glabrous distally, hairs all alike, 0.2-0.3 mm, apices unawned or awned, awns to 7 mm, straight;
paleas subequal to the lemmas, tapering to the apices, apices about 0.8 mm wide;
anthers 1-2 mm.
from late May to June.
= 28.
= 28.
Elymus multisetus
Elymus macrourus
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 macrourus grows on river banks and bars, lake shores, and hillsides in northwestern North America. Outside of North America, it grows across the Russian arctic, and extends south into the boreal forest. Plants growing on shifting river banks and bars often appear rhizomatous, as the lower internodes elongate in response to the disturbed substrate. Plants of E. macrourus differ from E. alaskanus (see next) in the shape of their glumes and their narrower glume margins, and from E. trachycaulus (p. 321) in their relatively short glumes and evidently hairy rachilla segments.
Three varieties of Elymus macrourus are recognized in Russian treatments. It is not clear to which, if any, of the Russian varieties North American plants belong. A circumboreal study is needed, using plants grown from seeds collected in the wild. Seeds available as E. macrourus through germplasm resources appear to be misidentified.
Elymus macrourus is one of the parents in both E. ×palmerensis (p. 340) and ×Elyhordeum pilosilemma (p. 284).
(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
