Plants annual. Culms 35-100
cm, erect or geniculate near the base, glabrous. Sheaths densely pubescent; auricles
absent; ligules 2-2.5 mm, glabrous,
acute, lacerate; blades 4-20 cm
long, 1-6 mm wide, pubescent on both surfaces. Panicles 10-20 cm long, 5-12 cm wide, open; branches 2-10 cm, spreading, ascending or drooping, rarely with
more than 3 spikelets. Spikelets
20-35 mm, usually shorter than the panicle branches, sides parallel or diverging
distally, moderately laterally compressed, with 5-9 florets. Glumes smooth or scabrous, margins
hyaline; lower glumes 6-14 mm,
1(3)-veined; upper glumes 10-20 mm,
3(5)-veined; lemmas 14-20 mm,
narrowly lanceolate, pubescent or puberulent, 7(9)-veined, rounded over the
midvein, margins hyaline, apices acuminate, bifid, teeth 1-3 mm; awns 15-30 mm, straight, arising 1.5 mm
or more below the lemma apices; anthers
1-1.4 mm. 2n = 14, 28.
Bromus sterilis is native to Europe, growing from Sweden southward.
It now grows in North America in road verges, fields, waste places, and
overgrazed rangeland. It is widespread in western and eastern North America, but
is mostly absent from the Great Plains and the southeastern states.
Annual 4-10 dm, the culm usually glabrous, but the sheaths and blades usually soft-hairy; blades 2-4 mm wide; ligule 1.5-2.5(-3.5) mm; infl relatively long, 1-2 dm, open, the elongate, capillary, often drooping branches mostly bearing only one or 2 spikelets, these mostly 25-31(-36) mm (to 5 cm incl. the awns), 4-8-fld, glabrous to strigose-puberulent; glumes subulate, the first 7-14 mm, 1-veined, the second 9-17 mm, 3-veined; lemmas very narrow, 13-18(-20) mm, 0.8-1.2 mm wide in side-view, 7-veined, the pair of veins nearest the midrib developed only distally, the outermost pair only proximally; awns 18-30 mm; palea almost equaling the lemma; anthers 0.9-1.6 mm; 2n=14, 28. Native of s. Europe, intr. in fields and waste places in much of the U.S., including most of our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.