Herbs, usually annual, erect or ascending, 10-30(-50) cm tall. Root fibrous, 7-10 cm × 3-5 mm, branched. Stems single or with ascending branches from near base, 3-5(-7) mm thick, sometimes slightly fistulose, smooth and glabrous. Leaves alternate; stipules absent; petiole absent or nearly so; leaf blade obovate to spoon-shaped, 1-3.5 × 0.5-1.5 cm, base cuneate, margin dentate, apex rounded. Inflorescence a compound pseudumbel, usually rather compact; primary involucral leaves 5, yellowish green, obovate-oblong, 3-4 × 0.8-1.4 cm, margin dentate, base attenuate, primary rays 5, to 2-4 cm, progressively shorter; cyathophylls 2, obovate, base rounded, margin dentate, apex rounded. Cyathium subsessile; involucre campanulate, ca. 2.5 × 2 mm, smooth and glabrous, lobes rounded, pilose at margin and inside; glands 4, pale brown, disklike, shortly stalked, shallowly concave. Male flowers many, exserted from involucre. Female flower: ovary slightly reaching margin of cup. Capsule trigonous-terete, 2.5-3 × 3-4.5 mm, with 3 vertical furrows, conspicuous, smooth, glabrous. Seeds ovoid, ca. 2 × 1.5 mm, dark brown, reticulately wrinkled; caruncle compressed, sessile. Fl. and fr. Apr-Oct. 2n = 42*.

This species is used medicinally.

Euphorbia helioscopia is a widespread and variable species and several subspecies have been proposed. Chinese material all belongs to subsp. helioscopia.

Fields, roadsides, scrub, margins of mixed forests. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Yunnan, Zhejiang [widely spread in N Africa, Asia, and Europe; introduced to North America].