Perennial with glabrous vegetative parts; stems at first prostrate but soon ascending to c. 25 cm, sometimes rooting at lower nodes. Lvs sessile, slightly amplexicaul, 1.5-7-(9) × 0.3-2-(2.5) cm, linear to lanceolate, often somewhat puckered, entire or slightly serrulate; apex acute. Infl. consisting of axillary, opposite racemes towards stem apices, > lvs, with many fls on spreading pedicels; peduncles and pedicels glandular-hairy; pedicels 3-5 mm long, soon elongating to exceed bracts at fruiting. Bracts usually linear, > calyx. Calyx 2-4 mm long; lobes oblong or ovate-oblong, glabrous, short-acuminate but blunt at tip. Corolla 5-7 mm diam., pink or pale pinkish, with darker veins. Capsule c. 3 mm wide, suborbicular, slightly wider than long, often ciliate. Seeds ovoid to oblong, convex on 1 side, flat on the other.