Erect annual herb 3–17 cm high, ± branched, decumbent or ascending, rooting at nodes; stems subquadrangular, ± pubescent and glandular. Leaves mostly opposite below and alternate above, petiolate; petiole 5–19 mm long, glandular-hairy; lamina broadly ovate, 9–20(–41) mm long, 6–15(–26) mm wide, cuneate or truncate at the base, margins dentate sometimes obscurely so, sparsely pubescent especially on the veins. Flowers axillary, solitary; pedicels filiform, 1–2.5(–4) cm long, not exceeding the leaves, glandular. Calyx lobes unequal, 1.2–2 mm long, glandular-hairy. Corolla white with upper lip brownish with spur, 3.5 mm long, 1 mm wide, lower lip 3-lobed, upper lip emarginate. Capsule 4 mm in diameter, 4-valved, valves spreading at dehiscence. Fig. 5, p. 21.