Perennial; stems glabrous, creeping, rooting at nodes. Lvs ± glabrous or sparsely hairy on petiole and undersurface of leaflets; petioles up to c. 100 mm long; leaflets usually elliptic, sometimes ovate or obovate, obtuse or obcordate, mucronate, cuneate at base, finely serrate, c. 5-20 mm long; lateral veins recurved and thickened toward leaflet margin; petiolules up to 1.5 mm long, subequal; stipules ovate-oblong, acuminate. Infls axillary, racemose, globose or ellipsoid, pedunculate, > lvs; fls numerous; pedicels up to 1 mm long; bracts subtending fls free, 2-6 mm long, but those at infl. base connate. Calyx tomentose on upper side, moderately hairy when inflated, with c. 20 indistinct veins, greatly inflated on upper side at fruiting; throat open, ± glabrous; calyx teeth slightly unequal, < corolla, erect at fruiting; 2 upper teeth longer, narrow-lanceolate, ± = or > tube, conspicuous on the inflated calyx; 3 lower teeth lanceolate; sinuses acute or obtuse. Corolla pinkish to reddish, persistent but ± enclosed by the inflated calyx at fruiting, 5-7 mm long. Pod glabrous, straight, < calyx, 2-4 mm long, 1-2-seeded; seeds c. 1.5-2 mm diam.