Annual, or rarely perennial, sometimes very tall tufts, or straggling or decumbent, rooting at nodes, sometimes floating. Ligule 0, or a fringe of hairs, the ligule area always well defined. Leaf-blade broad, flat. Panicle of racemes densely or loosely arranged along a central rachis. Racemes bearing densely packed, secund spikelets almost to base; rachis hispid, 3-angled; spikelets ± sessile or pedicelled, clustered in pairs or in short secondary racemelets, falling entire at maturity. Spikelets often hispid, often cuspidate or awned, 2-flowered; lower floret ♂ or Ø, upper floret ☿. Glumes membranous to membranous-herbaceous, unequal; lower much shorter, ± broadly ovate from clasping base, 3-5-nerved, often mucronate, upper ≈ spikelet, very convex, 3-7-nerved, ± acute, mucronate, cuspidate, or shortly awned. Lower floret: lemma ≈ upper glume and similar in texture, rarely smooth and shining; palea = lemma, hyaline, 2-keeled, or reduced or 0 in Ø florets. Upper floret: lemma subcoriaceous or crustaceous, faintly 5-nerved, awn straight or curved, or 0; palea ≈ lemma and similar in texture, keels rounded, margins broadened towards base; lodicules 2, cuneate, fleshy, glabrous; stamens 3; ovary apex glabrous, styles subterminal, free, stigmas pink, red, purple or black; caryopsis compressed, glabrous, embryo > ½ length of caryopsis, hilum punctiform, subbasal.