A perennial, erect to decumbent, up to 1 m tall, glabrous to sparsely hispid herb. Stem cylindrical below, angular above. Leaves opposite below, alternate and gradually smaller above, sessile or with upto 5 mm long petiole; lamina lanceolate or linear-lanceolate to oblong, 2-10 cm long, 0.5-1.8 (-2) cm broad, glabrous, subcordate or rounded at the base, margin entire, minutely spinulose, apex acute-acuminate or rarely obtuse; stipules ovate, 1-2 mm long, membranous. Flowers loosely clustered in upper leaf axils, greenish-white or pinkish-green; female sessile, male with 2.5-3.5 mm long pedicel. Calyx of male flowers 5-lobed, lobes shortly acuminate, abruptly incurved, ciliate, Stamens 5, c. 2 mm long. Achenes shining black, ovate, 1-1.5 mm long, acute, enclosed in 2-3-winged persistent calyx.