Annual herb; stem erect, to c. 1 m high, simple, rather angular, red-tinged, somewhat hairy. Petioles to c. 6 cm long, red-tinged. Lamina 3.5-11 × 1.5-5 cm (to 20 × 10 cm in cultivation), lanceolate-ovate or rhombic-ovate, glabrous above, ± puberulent on main veins beneath; base usually narrow-cuneate; apex obtuse and often mucronate. Infl. a dense spike-like panicle, usually interrupted near base, to c. 18 cm high, crimson, often with shorter lateral branches near base, the whole panicle pendulous from base. Rhachis hairy. Longer bracteoles 3-3.5 mm long, ovate with subulate tip; shorter bracteoles similar. Tepals 5, (1.2)-1.5-2.2 mm long, strongly imbricate, ± obovate, keeled; apex usually mucronate. Stigmas 3, crimson, > perianth. Frs slightly > perianth, circumscissile near the centre, ± urceolate. Seed 1-1.5 mm diam., orbicular, dark brown or black, shining.