Spikelets 2-nate, those of each pair differing in sex and in shape (slightly) and structure, one sessile, the other pedicelled (rarely solitary and accompanied by an empty pedicel) on the articulate fragile rhachis of 1- to many-jointed solitary racemes, terminating the culms and their branches; each raceme supported by a spatheole and forming with it a monostachyum; monostachya collected into a spatheate panicle; the fertile spikelets falling with the adjacent joint (if any) and the accompanying pedicel; joints and pedicels very finely filiform, with truncate tips. Florets 2, lower reduced to an empty valve, upper hermaphrodite in the sessile spikelets, ♂ or neuter in the pedicelled. Sessile spikelets subterete or when mature quite terete, rarely distinctly compressed from the back when in flower; callus short or more or less elongated and very acute, shortly bearded. Glumes subequal, coriaceous to subcoriaceous downwards; the lower 2-dentate or 2-mucronate with involute margins up to two-thirds or more, then finely keeled, the upper boat-shaped, rounded on the back, keeled, usually minutely emarginate and with a fine bristle from the notch, 3-nerved. Valve of lower floret hyaline, ciliate, of upper eciliate, more or less 2-fid, with the base, margins and lobes hyaline, awned from between the lobes, awn distinctly differentiated into column and bristle. Lodicules 2, minute, glabrous. Stamens 3. Stigmas laterally exserted; styles terminal, united at the base. Grain subterete to terete, shortly beaked from the persistent style-base; scutellum half the length of the grain. Pedicelled spikelets similar in outline to the sessile, but acuminate and usually somewhat longer, often with an elongated callus; lower glume with or without a terminal bristle, upper always muticous. Valves of both florets developed, hyaline, rarely the upper suppressed. —Perennial (? always) grasses with narrow blades and narrow stiff and contracted or open and more or less flaccid spatheate panicles.