Description from Flora of China
Chamaesyce indica (Lamarck) Croizat; Euphorbia indica var. angustifolia Boissier.
Herbs, annual, to 50(-100) cm tall. Root fibrous. Stems many from base, spreading or erect, often purplish tinged, sparsely white pubescent. Leaves opposite; stipules triangular, to 1.5 mm, laciniate; petiole to 3 mm; leaf blade ovate, to 3(-7) × 1.5(-2.5) cm, adaxially almost glabrous, abaxially glaucous, base obliquely rounded, margin obscurely toothed, apex rounded. Cyathia in axillary or terminal pedunculate capitate cymes, peduncle to 30 mm; involucre cuplike, ca. 1 × 1 mm, pubescent, marginal lobes triangular, apex acute; glands 4, green, rounded, appendages white, to 1 mm in diam., often smaller. Male flowers slightly exserted. Female flower exserted from involucre; ovary pubescent; styles free; stigma deeply 2-lobed. Capsule 3-angular-ovoid, ca. 1.5 × 2 mm, smooth, pubescent; fruiting pedicel ca. 1.5 mm. Seeds ovoid-tetragonal, ca. 1 × 0.75 mm, reddish brown, sides obscurely transversely furrowed; caruncle absent.
Until recently, this species was consistently named as Euphorbia hypericifolia, but that New World species is completely glabrous and with smaller capsules and dimpled seeds (see Raju & Rao, Indian J. Bot. 2: 202. 1979).
Disturbed areas, either seasonally inundated or irrigated and often with impeded drainage. Guangdong, Guizhou [tropical weed in Africa and Asia].