Annual, erect herb, 30-50 cm tall; stems angled, grooved, glabrous, sometimes tinged with red; leaves oblong, obtuse, often contracted above the rounded or cordate base, margins often waved or crisped, glabrous; petioles equal to or shorter than the lamina; flowers in axillary clusters, shortly pedicelled, bisexual, arranged in distinct leafy or leafless whorls; tepals 3+3, inner segments broadly ovate, reticulately veined, much enlarged in fruit and with broad, densely reticulated wings with margins irregularly toothed, teeth short, straight; stamens 6, attached to inner tepals; ovary 3-gonous, styles-3, stigma fimbriate; nutlets 3-angled, angles acute, winged, brown.