Plants perennial, annual, or biennial; usually cespitose, sometimes rhizomatous. Culms 5-190 cm. Sheaths closed to near the top, usually pubescent; auricles usually absent; ligules membranous, to 6 mm, usually erose or lacerate; blades generally flat, rarely involute. Inflorescences panicles, sometimes racemose, erect or nodding, open or dense, occasionally 1-sided; branches usually ascending to spreading, sometimes reflexed or drooping. Spikelets 5-70 mm, terete to laterally compressed, with 3-30 florets; disarticulation above the glumes, beneath the florets. Glumes unequal, usually shorter than the adjacent lemmas, always shorter than the spikelets, glabrous or pubescent, usually acute, rarely mucronate; lower glumes 1-7(9)-veined; upper glumes 3-9(11)-veined; lemmas 5-13-veined, rounded to keeled, glabrous or pubescent, apices entire, emarginate, or toothed, usually terminally or subterminally awned, sometimes with 3 awns or unawned; paleas usually shorter than the lemmas, ciliate on the keels, adnate to the caryopses; anthers (2)3. x = 7. Name from the Greek bromos, an ancient name for -oats-, which was based on broma, -food-.
Spikelets with several to many fls, eventually disarticulating between the lemmas and above the glumes, oval to narrowly oblong, subterete or laterally flattened; glumes somewhat unequal, shorter than the lemmas; lemmas 3-9-veined, 2-toothed at the tip, awnless or more often awned between the teeth; spikelets large, often in lax or drooping panicles; sheaths usually closed nearly to the top. 100, widespread in temp. reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.