Mary E. Barkworth, Julian J.N. Campbell and Bjorn Salomon
Culms 40–110 cm. Spikes 7–25 cm, somewhat 1-sided. Spikelets with 3–7 florets, the bases usually visible. Glumes 11–17 mm, long-acuminate or awned, awns to 11 mm; lemmas awned, awns 17–40 mm, longer than the lemma body, straight.
Elymus trachycaulus subsp. subsecundus grows primarily in the Great Plains. It may be confused with solitary-spikeleted plants of E. glaucus , from which it differs in its 1-sided spike and its stiffer, more basally concentrated leaves. Jozwik (1966) suggested that it is composed of derivatives from E. trachycaulus subsp. trachycaulus × Hordeum jubatum hybrids that are adapted to moist prairies. He noted that the unilateral spike is particularly characteristic of artificial hybrids between the two species, and is uncommon in other hybrids.