Densely tufted perennials, suffrutices with knotty rhizomatous base, or delicate annuals. Leaf-blades narrow or terete, sometimes early deciduous leaving sheaths and chlorophyll-bearing culms as the main photosynthetic organs. Panicle open or contracted. Spikelets 1-flowered with scarious glumes; lemma cylindrical; indurated, produced into a 3-branched awn; awn with or without a column, articulated at the base of the column or near the middle of the lemma, the branches, or at least the central one plumose; callus well-developed, pungent or minutely bifid, usually oblique; palea usually less than half as long as the lemma.