Plants annual. Culms (9)20–40 cm, erect or ascending. Sheaths sparsely pubescent or glabrous; ligules 0.8–1.5 mm, glabrous or hairy, obtuse; blades 5–20 cm long, 2–5 mm wide, abaxial surfaces glabrous, adaxial surfaces pilose. Panicles 2–7 cm long, 1–4 cm wide, erect, dense, obovoid, wedge-shaped at the base, sometimes interrupted; branches shorter than the spikelets, erect, straight or almost so, sometimes verticillate. Spikelets 12–25 mm, lanceolate, crowded, terete to moderately laterally compressed; florets 5–10, bases concealed at maturity; rachilla internodes concealed at maturity. Glumes scabrous to pubescent; lower glumes 3–4 mm, 3–5-veined; upper glumes 5–7 mm, 5–7-veined; lemmas 7–10 mm long, 1.5–2 mm wide, lanceolate, glabrous, obscurely 7-veined, rounded over the midvein, margins rounded, not inrolled at maturity, apices sharply acute, bifid, teeth shorter than 1 mm; awns 7–10 mm, flattened at the base, divaricate or recurved when mature, arising 1.5 mm or more below the lemma apices; anthers 0.3–0.5 mm. Caryopses shorter than the paleas, thin, weakly inrolled or flat. 2n = 14.
Bromus scoparius is native to southern Europe. It grows in waste places, and in the Flora region is recorded from California and New York.