Sterile brome

Bromus sterilis

Erect or geniculately ascending annual or biennial to 0.5 m high; culms slender to slightly stout, glabrous or pubescent.

Leaves with sheath usually pubescent; ligule c. 1.5 mm long; blade flaccid, 2–6 mm wide, softly hairy.

Panicle very lax, 10–20 cm long, branches mostly longer than the spikelets, spreading or nodding. Spikelets compressed, cuneate, 5–9-flowered, 25–65 mm long including awns. Glumes lanceolate, subulate, lower 1-nerved, 6–16 mm long; upper 3-nerved, 10–24 mm long. Lemma narrow-lanceolate, 8–23 mm long, with acute apical teeth 1–4 mm long, 5–7-nerved; awn slender, straight, 15–45 mm long. Palea 50–60% the length of the lemma.