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thickspike wheatgrass

Photo is of parent taxon

streambank wheatgrass

Habit Plants perennial, 22–130 cm, strongly rhizomatous; shoots often arising in clusters from the long slender rhizomes; foliage sometimes glaucous.
Culms

erect.

usually 22–60 cm.

Leaves

sheaths glabrous or pubescent;

blades 1.5–6 mm wide;

outer surfaces usually glabrous;

inner surfaces with appressed hairs.

Inflorescences

3.5–26 cm; erect to slightly nodding, 1 spikelet per node but occasionally with 2 at a few nodes;

internodes 3.5–15 mm;

disarticulation above the glumes; beneath each floret.

Spikes

6–10 cm;

internodes 3.5–10 mm, glabrous or sometimes scabrous.

Spikelets

8–31 mm, 1.5–3 times longer than the internodes, appressed, 3–11 florets, glabrous or hairy;

hairs to 1 mm.

10–17 mm.

Glumes

5–14 mm, 50–75% 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 keeled;

keels straight;

margins narrow, tapering from the base or from beyond mid-length;

tips acute to acuminate, sometimes mucronate or short-awned.

Lemmas

7–12 mm, glabrous to densely long-hairy; all hairs similar, sometimes scabrous;

tips acute to awned;

lemma awns; if present; to 2 mm; straight.

smooth or sometimes scabrous distally, mostly glabrous but margins sometimes hairy proximally.

Anthers

2.5–6 mm.

Elymus lanceolatus

Elymus lanceolatus ssp. riparius

Distribution
[WildflowerSearch map]
[BONAP county map]
Discussion

3 subspecies.

Elymus lanceolatus is a strongly rhizomatous wheatgrass that lacks or nearly lacks awns. It is most similar to Pascopyrum smithii, which has more basally concentrated leaves and glumes that taper from near the base and have curved midveins. It is also similar to E. trachycaulus, which is cespitose, has consistently glabrous lemmas, and has glumes 75–100% as long as the lemmas.

Clay soils in mesic to moist habitats, alkaline meadows, riparian terraces, sagebrush steppe. 50–1800 m. BR, BW, Owy, WV. CA, ID, NV, WA; Widespread in western North America. Native.

Elymus lanceolatus ssp. riparius is a strongly rhizomatous wheatgrass that grows in moister habitats than the other E. lanceolatus subspecies. Other subspecies have more or less hairy lemmas.

Source Flora of Oregon, volume 1, page 400
Barbara Wilson, Richard Brainerd, Nick Otting
Flora of Oregon, volume 1, page 400
Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa
E. canadensis, E. ciliaris, E. elymoides, E. glaucus, E. hirsutus, E. multisetus, E. repens, E. trachycaulus, E. tsukushiensis, E. violaceus, E. wawawaiensis
E. lanceolatus ssp. lanceolatus, E. lanceolatus ssp. psammophilus
Subordinate taxa
E. lanceolatus ssp. lanceolatus, E. lanceolatus ssp. psammophilus, E. lanceolatus ssp. riparius
Synonyms Agropyron dasystachyum Agropyron dasystachyum var. riparium, Agropyron riparium
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