Plants perennial; usually cespitose, sometimes rhizomatous. Culms 30-100 cm, usually erect, sometimes decumbent or geniculate. Leaves evenly distributed; sheaths open; auricles well developed; ligules membranous; blades flat to loosely involute. Inflorescences terminal spikes, erect, with 1 spikelet per node; internodes (7)10-20(28) mm at midlength, lower internodes often longer than those at midlength. Spikelets (8)12-25 mm, 1.1-1.5(2) times the length of the internodes, usually appressed, sometimes slightly divergent, with 4-9 florets; disarticulation above the glumes and below the florets. Glumes unequal, from shorter to slightly longer than the lowest lemma in the spikelets, lanceolate to oblanceolate, (3)4-5(7)-veined, usually acute to obtuse, occasionally truncate, narrowing beyond midlength, veins prominent; lemmas inconspicuously 5-veined, unawned or terminally awned, awns straight to strongly bent and divergent; anthers 4-8 mm. x = 7. Haplome St. Name from the Greek pseudo, -false-, and the genus Roegneria, an Asian taxon often included in Elymus.