Small annual herb, 5–35 cm tall; stems succose, erect, simple or branched, quadrangular, glabrous, rooting at the nodes. Leaves obscurely pinnately nerved or often uninerved; sessile; lamina linear, 1–5 x 0.1–0.5 cm, apex acute, base semi-amplexicaul or auriculate, margins spinose. Inflorescences lax raceme; pedicel 1–1.6 cm long, deflexed when fruiting; bracts lanceolate or deltate, 2–3 mm long. Calyx tubular to slightly campanulate, 1.5–2 mm long, 5-lobed; lobes divided to the base, linear or oblong, apex obtuse, densely grandular dots inside. Corolla pinkish-white to purple with white patch at lower lip, 7–10 mm long; upper lip oblong, apex rounded or truncate, 1.8‒3 mm wide; lower lip broadly 3-rounded lobes, 7–10 mm wide. Stamens 2 fertiles, 2 staminodes; posterior filaments straight, glabrous, 1‒1.5 mm long; anterior filaments staminodes, filliform, 1.3‒1.6, base yellow, buttress, apex uncinately curved. Capsules cylindric, apex acute, 5–12 x 0.7–1 mm, longer than calyx lobes. Seeds numerous, narrowly narrowly ellipsoid, ovoid, 0.25‒0.38 x 0.13‒0.21 mm, scrobiculate.
India, Cambodia, Vietnam, Malesia
Open places in paddy fields, at 100‒300 m altitudes; flowering and fruiting June–December