Herbs 5-20[-27] cm tall, annual. Stems slender, simple or laxly dichotomously branched, glabrous. Leaves alternate, sessile or subsessile; leaf blade oblong-obovate to oblanceolate, 6-10 mm, apical ones smaller and grading into bracts, glabrous, veins 3, base cuneate, margin entire, apex obtuse. Inflorescences dichotomously branched lax spikes or with flowers solitary; scapes absent; bracts linear, ca. 2 mm. Flowers sessile. Calyx tube (hypanthium) linear, with sparse glandular trichomes or glabrous; lobes partly connate, with 3 distinct and 2 connate into a shallowly 2-lobed segment. Corolla white or rose-purple, less than 2 mm, with sparse glandular trichomes; tube slightly longer than calyx lobes; throat appendages minute; labellum minute, subulate; lower pair of lobes longer than upper pair, lobe apices shallowly 2-lobed. Gynostemium 4-5 mm. Capsule thinly columnar, to 2 cm. Fl. and fr. Oct.

Paddy fields, swamps; below 1000 m. SE Fujian, Guangdong, Hainan, S Yunnan (Xishuangbanna) [Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam].