Plants not cespitose, strongly rhizomatous, often glaucous. Culms 35-75 cm tall, 1-2.5 mm thick, solitary or few together, glabrous or sparsely pubescent near the nodes. Leaves exceeded by the spikes; sheaths glabrous, smooth; auricles infrequently present, to 0.8 mm, the auricular location often with hairs to 2 mm; ligules 0.3-0.5 mm, truncate, erose; blades 4-29 cm long, 1-2(5) mm wide, flat, becoming involute when dry, stiff, adaxial surfaces scabrous, with scattered hairs to 2 mm, veins 7-11, subequal, prominently ribbed. Spikes 1.5-27 cm long, 4-15 mm wide, with 1 spikelet per node at midspike, sometimes with 2 at the lower nodes; internodes 7-20 mm, surfaces glabrous or strigillose, edges ciliate, cilia to 1 mm. Spikelets 16-25 mm, pedicellate, pedicels 1-2(5) mm, with 3-12 florets. Glumes subequal, 8-12 mm long, 0.5-1.5 mm wide, subulate, tapering from about 1/4 of their length, stiff, glabrous at least at the base, the central portion thicker than the margins, keeled, 0-1(3)-veined, veins inconspicuous at midlength; lemmas 7-12 mm, glabrous, awned, awns 2.3-6.5(12) mm; anthers 3.7-4.5 mm, dehiscent. 2n = 28.
Colo., Utah, Wyo., Calif., Nev., Ariz., Oreg.
Leymus simplex is found in meadows and drifting sand in southern Wyoming, and along the Green River in northeastern Utah.