Zanonia laxa Wallich, Pl. Asiat. Rar. 2: 29. 1831; Alsomitra laxa (Wallich) M. Roemer; Gynostemma crenulatum Ridley; Pestalozzia laxa (Wallich) Thwaites; Z. wightiana Arnott.

Stem slender, much branched, glabrous or sparsely puberulent. Leaves pedately 3-foliolate; petiole 1.5-4 cm, glabrous; median leaflet oblong-lanceolate, sometimes rhombic, 5-10 × 2-3 cm, papery, base broadly cuneate, apex acute or shortly acuminate; lateral leaflets ovate, 4-7 × 2-3.5 cm, glabrous, margin undulate-crenate; petiolule (2-)5-7 mm. Male flowers: inflorescence paniculate, terminal or axillary, (5-)10-30 cm, pubescent; bracts subulate-lanceolate, ca. 1 mm; pedicels filiform, 3-7 mm; bracteole subulate, small; calyx segments narrowly triangular-ovate, ca. 0.5 mm; corolla yellow-green; segments narrowly ovate-lanceolate, ca. 1.5 × 0.5 mm, glabrous, 1-veined, entire, acuminate at apex. Female inflorescence as male flowers; corolla segments narrowly triangular; ovary globose, ca. 1 mm in diam.; styles 3, free, apex 2-fid. Fruit yellow-green, globose, 8-10 mm, glabrous, indehiscent. Seeds pale gray, broadly ovate, ca. 4 mm in diam., compressed, both surfaces papillate, base rounded, apex acute. Fl. Aug, fr. Aug-Sep.

One of us (Jeffrey) would treat this taxon as a synonym of Gynostemma pentaphyllum.

Dense forests in valleys. Guangxi, Hainan, SE Yunnan [India, Indonesia, Malaysia, Myanmar, Nepal, Philippines, Thailand, Vietnam].