16. Euphorbia thymifolia Linnaeus, Sp. Pl. 1: 454. 1753.
千根草 qian gen cao
Chamaesyce thymifolia (Linnaeus) Millspaugh.
Herbs, annual, 10-20 cm tall. Root fibrous. Stems slender and thin, many from base, usually prostrate, 1-2(-3) mm thick, with many adventitious roots, sparsely pilose. Leaves opposite; stipules lanceolate or linear, 1-1.5 mm, easily fallen; petiole ca. 1 mm; leaf blade rounded or cordate, margin usually finely serrulate, occasionally entire, both surfaces pubescent. Cyathia single or numerous clustered and axillary, peduncle 1-2 mm, sparsely pilose; involucre campanulate to turbinate, ca. 1 × 1 mm, outside shortly pilose, marginal lobes 5, ovate; glands 4, appendage white. Male flowers few, slightly exserted from involucre. Female flower: pedicel short; ovary shortly pubescent; styles free; stigma 2-lobed. Capsule 3-angular-ovoid, ca. 1.5 × 1.3-1.5 mm, smooth, shortly pubescent. Seeds ovoid-tetragonal, ca. 0.7 × 0.5 mm, dark red, each side with 4 or 5 transverse furrows; caruncle absent. Fl. and fr. Jun-Nov.
Roadsides, grasslands, scrub, fields, very common. Fujian, Guangdong, Guangxi, Hainan, Hunan, Jiangsu, Jiangxi, Taiwan, Yunnan, Zhejiang [widely spread in warm countries of both hemispheres].
This species is used medicinally.