Tufted annual, culms erect, to 80 cm high. Leaves with soft, spreading hairs; blade flat or loosely folded, to 15 cm long and 10 mm wide, lightly scabrous; ligule glabrous, torn at apex, 2–4 mm long. Inflorescence a loose panicle, to 15 cm long (excluding awns), branches initially sub-erect, usually drooping at maturity, the longest not or barely longer than the spikelets. Spikelets 4–10-flowered, oblong, 40–60 mm long (excluding awns), florets separating toward maturity; lower glume 1-nerved, 13–20 mm long, upper glume 3-nerved, 20–27 mm long; lemma 20–30 mm long, excluding awn, dorsally rounded, strongly scabrous, with 2 membranous apical lobes 4–7 mm long; awn 35–60 mm long. Flowers Sep.–Nov.
LoM, MuM, Wim, GleP, Brid, VVP, VRiv, MSB, RobP, MuF, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, EGU, WPro, HSF, HNF, OtR, Strz, VAlp. Naturalised in all States, widely in temperate countries. Indigenous to the Mediterranean region and south-west Europe. Occurs throughout Victoria on disturbed soil (particularly roadsides) and a common crop weed in the north and west of the State.
The name Bromus rigidus Roth. has been applied to specimens collected from Walpeup in the Mallee having an erect, more compact inflorescence with the longest panicle branches mostly less than 15 mm. Other differences are attributed to this taxon, e.g. elliptical abscission scar on the callus (cf. circular for B. diandrus), but these have all been demonstrated as being variables within a continuum having 'typical' B. diandrus and B. rigidus as the end points.
