Herbs annual, 15-40 cm tall. Stem erect, much branched, obscurely striate, ribbed; branches oblique, pilose. Leaves shortly petiolate; leaf blade bluish green, terete or clavate, 0.4-2 cm × 0.5-0.8 mm, pubescent or becoming glabrous at maturity, base attenuate, apex obtuse or acute. Flowers bisexual, usually 1-3 per glomerule in almost all leaf axils. Perianth greenish, pubescent or occasionally subglabrous; 3 larger appendages spreading, black-brown, purple-red, or brown veined, winglike, lanceolate to narrowly ovate; 2 other appendages usually erect, subulate or tuberculate; sometimes all 5 appendages winglike but then 2 wings small. Stamens 5; filaments slightly exserted; anthers oblong. Style very short; stigmas 2, light yellow. Pericarp thickly membranous. Seed ovoid; perisperm white, farinose. Fl. and fr. Aug-Sep.