33. Euphorbia helioscopia Linnaeus, Sp. Pl. 1: 459. 1753.
泽漆 ze qi
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*.
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].
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.