Perennial herbs, erect or decumbent, branched, slightly succulent, glabrous; stems creeping, stoloniferous rooting at nodes below, glandular pubescent above; leaves sessile or subsessile, opposite, oblong-lanceolate, entire or serrate, apex obtuse; flowers in axillary, 7.5-15 cm long, lax racemes; pedicels filiform, longer than calyx; bract linear-lanceolate; ebracteolate; calyx-segments 4, oblong-lanceolate, sub-acute; corolla white or pink, rotate, tube short, 4-lobes, spreading; stamens 2, exerted, anther cells not parallel, obtuse, tips confluent; ovary 2-celled, ovules many; style simple, stigma sub-capitate; capsule broadly or ovate, orbicular somewhat compressed laterally, turgid, orbicular, 2 grooved with minute, glandular hairs; seeds many or few, smooth, biconvax.