Elymus lanceolatus
Elymus dahuricus
streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass
Dahurian wild rye
22-130 cm, erect;
nodes glabrous.
30-130 cm, erect;
nodes 4-7, mostly exposed, usually glabrous, occasionally short-hairy.
often mostly basal, sometimes more evenly distributed;
sheaths glabrous or pubescent;
auricles usually present on the lower leaves, 0.5-1.5 mm;
ligules 0.1-0.5 mm, erose, sometimes ciliolate;
blades 1.5-6 mm wide, generally involute, abaxial surfaces usually glabrous, adaxial surfaces strigose, ribs subequal in size and spacing.
evenly distributed;
sheaths glabrous;
auricles minute or absent;
ligules 0.5-1 mm;
blades 3-18 mm wide, lax, usually pale green, sometimes glaucous, adaxial surfaces usually smooth or scabrous on the veins, sometimes sparsely pilose.
3.5-26 cm long, 0.5-1 cm wide, erect to slightly nodding, usually with 1 spikelet per node, sometimes with 2 at a few nodes;
internodes 3.5-15 mm long, 0.1-0.8 mm wide, glabrous or hairy.
7-23 cm long, 1-2.5 cm wide, usually slightly nodding, sometimes erect, usually with 2 spikelets per node, occasionally with 1 spikelet at some nodes;
internodes 3-6 mm long, 0.2-0.8 mm thick at the thinnest sections, angles usually with scattered hairs.
8-31 mm, 1.5-3 times longer than the internodes, appressed, with 3-11 florets;
rachillas glabrous or hairy, hairs to 1 mm;
disarticulation above the glumes, beneath each floret.
10-15 mm, appressed to divergent, often purplish, with (2)3-4(5) florets, lowest florets functional;
disarticulation above the glumes, beneath each floret.
subequal, 5-14 mm long, 1/2 - 3/4 the length of the adjacent lemmas, 0.7-1.3 mm wide, lanceolate, glabrous or hairy, smooth or scabrous, 3-5-veined, flat or weakly, often asymmetrically keeled, keels straight, margins narrow, tapering from the base or from beyond midlength, apices acute to acuminate, sometimes mucronate or shortly awned;
lemmas 7-12 mm, glabrous or hairy, hairs all alike, sometimes scabrous, acute to awn-tipped, awns to 2 mm, straight;
paleas about equal to the lemmas, keels straight below the apices, smooth or scabrous proximally, sometimes hairy, scabrous distally, intercostal region glabrous or with hairs, apices 0.2-0.3 mm wide;
anthers (2.5)3-6 mm.
equal, the bases flat, not indurate, veins evident, glume bodies 6-9 mm long, 1-1.5 mm wide, linear-lanceolate, entire, widening or parallel-sided above the base, (1)3-5(7)-veined, veins scabrous, margins hyaline or scarious, awns (0)1-5 mm, straight or outcurving;
lemmas (5)7-11 mm, usually glabrous and smooth throughout, sometimes scabrous to hispid distally and on the margins, marginal hairs not markedly longer than those elsewhere, awns (3)6-17(20) mm, usually somewhat outcurving from near the base;
paleas 7-11 mm, keels spinose-ciliate, apices obtuse or truncate;
anthers 1.5-3.5 mm.
from May to July.
= 28.
= 42.
Elymus lanceolatus
Elymus dahuricus
Elymus lanceolatus grows in sand and clay soils and dry to mesic habitats. It is found primarily in the western half of the Flora region, between the coastal mountains and 95° W longitude, with the exception of E. lanceolatus subsp. psammophilus, which extends around the Great Lakes. Three subspecies are recognized, primarily on the basis of their lemma and palea pubescence.
Elymus lanceolatus is primarily outcrossing, and hybridizes with several species of Triticeae. Elymus albicans (p. 334) is thought to be derived from hybridization with the awned phase of Pseudoroegneria spicata (p. 281). Judging from specimens of controlled hybrids, hybridization with E. trachycaulus (p. 321) and unawned plants of P. spicata probably occur, but would be almost impossible to detect without careful observation in the field. Experimental hybrids are partially fertile, and capable of backcrossing to either parent (Dewey 1965, 1967, 1968, 1975, 1976).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus dahuricus is widespread in temperate central and eastern Asia. Like E. tsukushiensis (p. 336), it is a hexaploid with an StYH genome constitution. It has been introduced for reclamation in some parts of western North America. It is most likely to be confused with E. glaucus (p. 306), from which it differs in its palea shape. Because its presence in the region became known shortly before completion of this volume, its distribution in the region is not known. Several varieties have been described in Asia; only Elymus dahuricus Turcz. ex Griseb. var. dahuricus has been introduced to North America.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lemmas densely hairy, hairs flexible, some 1 mm long or longer | subsp. psammophilus |
1. Lemmas glabrous or with stiff hairs shorter than 1 mm. | → 2 |
2. Lemmas with hairs, not scabrous | subsp. lanceolatus |
2. Lemmas smooth, sometimes scabrous distally, mosdy glabrous, sometimes the lemma margins hairy proximally | subsp. riparius |
BC
OR
WA
CalFlora
Flora NW
IL Wildflowers
MI Flora
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
