Trailing or climbing herb; stem prostrate, terete, glabrous or pubescent; leaves sessile, linear-oblong, much elongate, subacute at apex, white, silky tomentose; flowers sessile, axillary, solitary or fascicled; bracts small, linear-lanceolate, hirsute, often with 2- filiform, calyx hairy, sepals-5, elliptic-lanceolate, truncate, unequal; corolla pure white, broadly campanulate, 5-plaited, glabrous; stamens-5, filaments unequal, anthers short, oblong; ovary 2-4 locular, 4-ovuled; style slender; stigma bifid, elongate; capsules 4-seeded, ovoid, glabrous; seeds minute, glabrous, brown.