Difference between revisions of "Elymus lanceolatus"
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Revision as of 21:19, 16 December 2019
Plants strongly rhizomatous, sometimes glaucous. Culms 22-130 cm, erect; nodes glabrous. Leaves 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. Spikes 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. 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. Glumes 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. 2n = 28.
Distribution
Oreg., Nev., Colo., N.Mex., Alaska, Ill., Mont., Wyo., Mich., Wis., Idaho, Alta., B.C., Man., Ont., Sask., Yukon, Wash., Ariz., Calif., N.Dak., Nebr., S.Dak.
Discussion
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).
Selected References
None.
Lower Taxa
Key
| 1 | Lemmas densely hairy, hairs flexible, some 1 mm long or longer | Elymus lanceolatus subsp. psammophilus |
| 1 | Lemmas glabrous or with stiff hairs shorter than 1 mm. | > 2 |
| 2 | Lemmas with hairs, not scabrous | Elymus lanceolatus subsp. lanceolatus |
| 2 | Lemmas smooth, sometimes scabrous distally, mosdy glabrous, sometimes the lemma margins hairy proximally | Elymus lanceolatus subsp. riparius |