Elymus lanceolatus
Elymus albicans
streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass
Montana wheatgrass, Montana wild rye
22-130 cm, erect;
nodes glabrous.
40-100 cm, erect or decumbent only at the base, glabrous.
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.
somewhat basally concentrated;
sheaths glabrous;
auricles usually present, to 0.8 mm;
ligules 0.2-0.5 mm, ciliolate;
blades 1-3 mm wide, usually involute, adaxial surfaces scabrous to strigose.
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.
4-14 cm long, 1.5-2.5 cm wide including the awns, 0.3-0.8 cm wide excluding the awns, erect, with 1 spikelet per node;
internodes 6-14 mm long, 0.2-0.4 mm wide, glabrous or pubescent beneath the spikelets.
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.
10-18 mm, 1.5-2 times longer than the internodes, appressed to ascending, with 3-7 florets;
rachillas strigillose;
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.
subequal, 1/2 as long as to almost equaling the adjacent lemmas, glabrous or hairy, weakly keeled, keels and adjacent veins smooth to evenly and strongly scabrous from the base to the apices, margins 0.2-0.3 mm wide, apices acute, acuminate, or shortly awned;
lower glumes 4-8 mm;
upper glumes 4.5-8 mm;
lemmas 7.5-9.5 mm, glabrous or densely hairy, awns 4-12 mm, at least some strongly divergent;
paleas subequal to the lemmas, tapering to the 0.1-0.3 mm wide apices;
anthers 3-5 mm.
= 28.
= 28.
Elymus lanceolatus
Elymus albicans
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 albicans grows primarily in the central Rocky Mountains and the western portion of the Great Plains. It tends to grow in shallow, rocky soils on wooded or sagebrush-covered slopes, rather than in deep loams. It is derived from hybrids between Pseudoroegneria spicata (p. 281) and E. lanceolatus (p. 327). In practice, it is probably restricted to hybrids involving the awned variant of Pseudoroegneria spicata, because the hybrid origin of those involving the unawned variant would probably not be recognized.
Populations of Elymus albicans differ in their reproductive abilities (Dewey 1970). In some, most plants yield good seed; in others, most plants are sterile. Some fertile populations appear to be self-perpetuating; others appear to consist of recent hybrids and some backcrosses. Although treated here as a species, E. albicans could equally well be treated as a hybrid in xPseudelymus (p. 282), but the combination has not been published. Plants with glabrous lemmas, presumed to be derived from crosses with glabrous individuals of E. lanceolatus, have sometimes been treated as a distinct taxon, e.g., Agropyron albicans var. griffithsii (Scribn. 8c J.G. Sm.) Beetle or A. griffithsii Scribn. & J.G. Sm.; they are not formally recognized here.
(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
