Leymus

Plants perennial; sometimes cespitose, often rhizomatous. Culms 10-350 cm, erect, with extravaginal branching. Leaves basal or evenly distributed; sheaths open; auricles usually present; ligules membranous, truncate to rounded; blades often stiff, adaxial surfaces usually with subequal, closely spaced, prominently ribbed veins, sometimes with unequal, widely spaced, not prominently ribbed veins. Inflorescences usually distichous spikes with 1-8 spikelets per node, sometimes panicles with (2)3-35 spikelets associated with each rachis node; rachises with scabrous or ciliate edges; internodes 3.5-12(15) mm. Spikelets 1/2-3 3/4 times the length of the rachis internodes, usually sessile, sometimes pedicellate, pedicels to 5 mm, appressed to ascending, with 2-12 florets, the terminal floret usually reduced; disarticulation above the glumes, beneath the florets. Glumes usually 2, usually equal to subequal, the lower or both glumes sometimes reduced or absent, lanceolate and narrowing in the distal 1/4, or lanceolate to subulate and tapering from below midlength, pilose or glabrous, sometimes scabrous, 0-3(7)-veined, veins evident at least at midlength, sometimes keeled, keels straight or almost so, apices acute, acuminate, or tapering to an awnlike tip, if distinctly awned, awns to 4 mm; lemmas glabrous or with hairs, sometimes scabrous distally, inconspicuously 5-7-veined, rounded over the back proximally, sometimes keeled distally, keels not conspicuously scabrous distally, apices acute, unawned or awned, awns usually to 7 mm, sometimes 16-33 mm, straight; paleas slightly shorter than to slightly longer than the lemmas, keels usually scabrous or ciliate on the distal portion, sometimes throughout; lodicules 2, shortly hairy, lobed; anthers 3, 2.5-10 mm. Caryopses with hairy apices. x = 7. Haplomes Ns, Ns or Xm. Name an anagram of Elymus.

Similar to Elymus, and like it with the rachilla twisted and the glumes displaced to stand side by side subtending the spikelets, but outcrossing, with anthers mostly over 3 mm, and with awnless or only shortly awned lemmas; plants tufted or more often on ±elongate rhizomes. 30, N. Hemisphere.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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