Trailing herb. Stem prostrate, terete, glabrous. Lvs terete or weakly 3-angled, obtuse and mucronate at apex, clavate, tapering to shortly connate base, (5)-20-30-(50) × (4)-5-6-(10) mm; margins papillate. Fls 2-4 cm diam. Calyx glabrous; sepal keels smooth. Petals purple with white base, in 2 rows, 10-30 mm long. Stamens 5-7 mm long; filaments hairy at base; anthers whitish yellow. Capsule 5-12 mm diam., valves with widely divergent expanding keels; placental tubercle 2-lobed. Seeds pale brown to brown, weakly rugose or smooth, c. 1 mm long.