Elymus lanceolatus
Elymus wawawaiensis
streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass
Snake River wheatgrass, wawawai wild rye
22-130 cm, erect;
nodes glabrous.
(15)50-130 cm, erect, mostly glabrous;
nodes usually glabrous, sometimes slightly pubescent.
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.
more or less evenly distributed;
basal sheaths glabrate, margins not evidently ciliate;
auricles absent or to 1.2 mm;
ligules 0.1-1.1 mm;
blades to 28 cm long, 1.7-5 mm wide, involute when dry, adaxial surfaces usually densely pubescent, rarely sparsely pubescent.
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.
5-20 cm long, 2.5-3 cm wide including the awns, erect to slightly nodding, with 1 spikelet per node;
internodes 5-12 mm long, about 0.2 mm thick, about 0.3 mm wide, glabrous 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.
10-22 mm long, about twice as long as the internodes, 2-8.5 mm wide, appressed, with 4-10 florets;
rachillas glabrous;
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.
4-10 mm long, 0.5-1.3 mm wide, narrowly lanceolate, widest at or below midlength, glabrous, often glaucous, 1-3-veined, flat or weakly keeled, margins 0.1-0.2 mm wide, widest near midlength, apices usually acuminate, awned or unawned, awns to 6 mm;
lemmas 6-12 mm, smooth or slightly scabrous, margins often sparsely pubescent proximally, apices awned, longest awns in the spikelets 9-28 mm, strongly divergent;
paleas 7.2-10.5 mm, keels scabrous distally, tapering to the 0.2-0.3 mm wide apices;
anthers 3.5-6 mm.
= 28.
= 28.
Elymus lanceolatus
Elymus wawawaiensis
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 wawawaiensis grows primarily in shallow, rocky soils of slopes in coulees and reaches of the Salmon, Snake, and Yakima rivers of Washington, northern Oregon, and Idaho. There are also a few records from localities at some distance from the Snake River and its tributaries. These probably reflect deliberate introductions. C.V. Piper, who worked for the U.S. Department of Agriculture in southeastern Washington from 1892-1902, frequently distributed seed to farmers in the region from populations that he considered superior; he considered E. wawawaiensis to be a superior form of what is here called Pseudo-roegneria spicata (p. 281). Another source of introduced populations is 'Secar', a cultivar of E. wawawaiensis that is recommended as a forage grass for arid areas of the northwestern United States.
Elymus wawawaiensis resembles a vigorous version of Pseudoroegneria spicata, and was long confused with that species. It differs in its more imbricate spikelets and narrower, stiff glumes. In its primary range, E. wawawaiensis is often sympatric with P. spicata, but the two tend to grow in different habitats, E. wawawaiensis growing in shallow, rocky soils and P. spicata in medium- to fine-textured loess soil. The two species also differ cytologically, E. wawawaiensis being an allo-tetraploid, and P. spicata consisting of diploids and autotetraploids.
(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
