Elymus lanceolatus
Elymus glaucus
streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass
blue or western wild-rye, blue wild-rye, common western wildrye
22-130 cm, erect;
nodes glabrous.
30-140 cm, erect or slightly decumbent;
nodes 4-7, mostly exposed, usually glabrous, sometimes puberulent.
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 scabrous or smooth, glabrous or, particularly those of the lower leaves, retrorsely puberulent to hirsute, often purplish;
auricles usually present, to 2.5 mm, often purplish;
ligules to 1 mm, truncate, erose-ciliolate or entire;
blades 2-13(17) mm wide, usually lax, sometimes slightly involute, adaxial surfaces glabrous, scabrous, or strigose on the veins, sometimes pilose to villous.
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.
5-21 cm long, (0.2)0.5-2 cm wide, erect to slightly nodding, rarely somewhat pendent, usually with 2 spikelets per node, sometimes with 1 at all or most nodes, rarely with 3 at some nodes;
internodes 4-8(12) mm long, 0.15-0.5 mm thick at the thinnest sections, angles scabrous, glabrous below 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.
8-25 mm, sometimes purplish at higher latitudes and elevations, appressed to slightly divergent, with (1)2-4(6) florets, lowest florets functional;
disarticulation above the glumes and 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, 3/4 as long as or equaling the adjacent lemmas, bases often overlapping, usually flat and thin with evident venation, glume bodies (6)9-14(19) mm long, 0.6-1.5(2) mm wide, linear-lanceolate, entire, widening above the base, (1)3-5(7)-veined, 2-3 veins extending to the apices, glabrous, veins smooth or evenly scabrous, margins 0.1-0.2 mm wide, whitish hyaline, tapering towards the apices, unawned or awned, awns to 5(9) mm, straight;
lemmas (8)9-14(16) mm, glabrous, scabrous, or short-hirsute, awns (0)1-30(35) mm, usually straight to flexuous, sometimes slightly curving;
paleas 7-13 mm, keels straight or slightly concave, usually scabrous to ciliate, apices often bidentate;
anthers 1.5-3.5 mm.
from May to July.
= 28.
= 28.
Elymus lanceolatus
Elymus glaucus
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 glaucus grows in moist to dry soil in meadows, thickets, and open woods. It is widespread in western North America, from Alaska to Saskatchewan, and south to Baja California and New Mexico. It is also sporadic, sometimes appearing transitional to E. trachycaulus (p. 321), from the northern Great Plains to southern Ontario and New York and, as a disjunct, on rocky sites in the Ozark and Ouachita mountains.
Populations can differ greatly in morphology, especially in rhizome development, leaf width, pubescence, and the prevalence of solitary spikelets; their crossing relationships are partly correlated with such variation (Snyder 1950, 1951; Stebbins 1957, Wilson et al. 2001). Rhizome development and the production of solitary spikelets may also be environmental responses. Rhizomatous plants are more common on unstable slopes or sandy soils. Plants with solitary spikelets are more common on poor soil or in shade. They are often confused, particularly in the herbarium, with E. stebbinsii (p. 329) or E. trachycaulus. They differ from E. stebbinsii in their shorter anthers and awned glumes. Distinction from E. trachycaulus can be difficult with herbarium specimens, but is generally easy in the field, E. glaucus having more evenly leafy culms, laxer and wider blades, more tapered glumes that are almost always awned, and shorter anthers than the sympatric E. trachycaulus.
There are reports of natural hybrids with several other species of Elymus, including E. elymoides (p. 318), E. multisetus (p. 318) (see E. ×hansenii, p. 340), E. trachycaulus, and E. stebbinsii. These hybrids often appear at least partially fertile. Elymus glaucus can also form intergeneric hybrids with Leymus and Hordeum (see ×Elyleymus, p. 343, and ×Leydeum, p. 368).
The following three subspecies appear to be morphologically, ecologically, and geographically distinct. Plants found at elevations of up to 2200 m along the Pacific coast, with hairy leaf blades and lemma awns usually shorter than 20 mm, have been called subsp. jepsonii (Burtt Davy) Gould, but Wilson et al. (2001) demonstrated that such plants are neither genetically nor ecologically distinct from those with glabrous leaf blades; they are included here in subsp. glaucus.
(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 |
1. Lemma awns (0)1-5(7) mm long; glume awns 0-2 mm long | subsp. virescens |
1. Lemma awns (5)10-30(35) mm long; glume awns (0.5)1-9 mm long. | → 2 |
2. Blades 4-17 mm wide, adaxial surfaces glabrous or strigose, occasionally pilose to hirsute with hairs of fairly uniform length; glume awns (0.5)1-5(9) mm long | subsp. glaucus |
2. Blades 3-8 mm wide, densely short-pilose with scattered longer hairs; glume awns 3-8 mm long | subsp. mackenziei |
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