Erect or diffused, annual herb; stem 4-angular, profusely branched, glabrous; leaves falsely whorled or alternate, nearly sessile, much narrowed at the base, linear-lanceolate, acute or subacute, entire; stipules quickly disappearing; flowers minute, white in terminal or axillary, slender, compound cymes or panicles; peduncles longer than leaves, pedicels filiform; bracts inconspicuous; sepals-5, elliptic or round-oval, obtuse, persistent; petals absent; stamens 3-5, filaments short, filiform; ovary ovoid or ellipsoid, 3-5 celled; style 3, short or linear, ovules many, axile; capsules dehiscent, membranous, ellipsoid, almost as long as the sepals, many seeded; seeds dark, reddish-brown, reniform with raised tubercles.