31. Bromus, Linn.

Annual or perennial grasses, of very various habit. Leaves flat, often flaccid ligules membranous. Spikelets laterally compressed, 4-to many-flowered, arranged in a lax or contracted panicle, rarely reduced to a raceme; rhachilla disarticulating above the two outer glumes and between the flowering glumes. Two outer glumes unequal, empty, persistent, 1–7-nerved. Flowering glumes lanceolate to oblong, rounded on the back or keeled, 5ndash;9-nerved, usually 2-toothed at the apex, awned from between the teeth or rarely from below them. Palea 2-toothed, ciliolate or scabrid on the keels. Lodicules 2, oblong or lanceolate, entire or lobed. Stamens usually 3. Ovary oblong or obovoid, furnished with a 2ndash;3-lobed hairy cushion-like appendage at the summit; styles short, placed laterally on the appendage; stigmas plumose. Grain linear or oblong, furrowed, adherent to the palea; hilum long, narrow-linear.

Species 40 or 50, most abundant in the north temperate zone and in South America, rare on the high mountains of the tropics. The single indigenous species is a common Australian plant.