Annual, often much-branched, erect herb, to c. 1 m high, glabrous or nearly so (apart from infl. rhachis). Petioles of lower lvs to c. 10 cm long. Lamina of middle and upper cauline lvs 3-8 × 1-6 cm, lanceolate, ovate or rhombic, often red-tinged, glabrous at maturity; base cuneate; apex obtuse to acute. Infl. a dense spike-like panicle, interrupted towards the base, ± crimson, usually with a few branches, but simpler in plants on impoverished soils; main spike to c. 25 cm high, drooping towards apex; lateral spikes c. 10 cm or more, also drooping. Rhachis hairy. Longer bracteoles 3-4 mm long, ovate; apex subulate; keel greenish to red; shorter bracteoles similar. Tepals (4)-5, subequal, 1.5-2.3 mm long, scarcely imbricate, slightly larger in ♂ fls, oblong or obovate-oblong; keel darker than rest of tepal; apex obtuse, acute or mucronate. Stigmas 3, > perianth. Fr. ± broadly ellipsoid, = or < perianth, circumscissile, ± rounded at apex. Seed 1-1.3 mm diam., orbicular, shining dark brown.