Annual, weak herb; stem scabrulous-glabrous, quadrangular. Leaves 4-6 in a whorl, elliptic, lanceolate or oblanceolate, 1-3 (-5) x 0.5-1 cm, obtuse or rarely acute, midrib and margin retrorsely aculeolate, margin ± revolute, petiole ± absent. Inflorescence of axillary and terminal cymes; branches distantly divaricate, 1-7-flowered; peduncle and pedicel mostly straight, the later c. 5 mm long, sometimes sharply bent just under the fruit. Corolla white or greenish yellow, glabrous, c. 1 mm long, lobes ovate, obtuse. Fruit didymous, glabrous or hairy, 2-3 mm long, black when ripe.