Annual, suberect, 50-60 cm tall herb. Stem woody, with scaly bark, glabrous. Leaves 3-costate, elliptic-oblong or lanceolate to narrowly ovate, 1.5-6 cm long, 0.5-2.0 cm broad, glabrous, serrate, basal serratures not prolonged into filiform appendages, obtuse; petiole 3-15 mm long, hirsute; stipules subulate-filiform, c. 5 mm long. Cyme a fascicle of 2-5 (-8) flowers, antiphyllous, very shortly pedunculate. Flowers yellow, 5-6 mm across; bracts minute. Sepals linear-oblong, c. 1.5-2.5 mm long, apiculate. Petals oblong-obovate, as long as sepals. Stamens as many as or twice the number of petals, filaments c. 1.5-2 mm long. Carpels 3; ovary oblong-ovate to linear, 3-loculed, hairy; style short, stigma capitate. Capsules 2-5(-8) in each fascicle, sessile, 1-1.5 cm long, with 1-2 mm long entire beak, somewhat triangular, pubescent, 3-loculed, locules without transverse septa. Seeds wedge shaped, c. 1.5 mm long, angular, black, obliquely truncate at both ends.