Herbaceous annuals or perennials. Spikelets borne in panicles, racemes or spikes, 2-flowered, the lower floret male or sterile, rarely bisexual, the upper always bisexual; spikelets falling entire (but glumes persistent in Arundinelleae); lemmas 5-many-nerved, the lemma and palea of the upper floret usually crustaceous; lodicules truncate; stamens usually 3, rarely fewer.

Leaf anatomy: vascular bundles oval or circular in section; bundle-sheath single or rarely double; chlorenchyma cells radially arranged, restricted to the immediate region around the vascular bundles; 2-celled micro-hairs present.

Embryo: scutellum cleft and internode in vascular trace present, but epi¬blast absent; first leaf rolled.