细齿大戟 xi chi da ji

Chamaesyce bifida (Hooker & Arnott) T. Kurosawa; C. harmandii (Gagnepain) Soják; C. vachellii (Hooker & Arnott) H. Hara; Euphorbia coudercii Gagnepain; E. coudercii f. glaberrima Gagnepain; E. harmandii Gagnepain; E. reinwardtiana Steudel; E. serrulata Reinwardt ex Blume (1825), not Thuillier (1799); E. vachellii Hooker & Arnott.

Herbs, annual, 20-40(-50) cm tall. Root fibrous, 3-5 mm. Stems woody at base, many branched, ascending, each branched again, 3-5 mm thick, internodes terete, conspicuous. Leaves opposite; stipules membranous, spinelike-triangular, 0.4-0.6 mm, free or connate at base, caducous; petiole less than 3 mm; leaf blade long elliptic to widely linear, 1-2.5 cm × 2-5 mm, base subtruncate or slightly oblique, margin finely serrulate, apical short tip on fine serrulations, apex obtuse or acuminate; main vein prominent abaxially, impressed adaxially, lateral veins pinnate, clear. Cyathia clustered, occasionally single; involucre cuplike, ca. 1 × 1 mm, marginal lobes 5, triangular, apex lacerate; glands 4, appendages pink-red, wider than glands. Male flowers numerous, slightly exserted from involucre. Female flower exserted from involucre; ovary smooth, glabrous; styles free; stigma 2-lobed. Capsule 3-angular, ca. 2 × 2 mm, smooth, nearly glabrous. Seeds 3-angular, ca. 1.5 × 1 mm, brown, sides transversely furrowed; caruncle absent. Fl. and fr. Apr-Oct.

Roadsides, forest margins, scrub, fields. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Jiangxi, Jiangsu, Taiwan, Yunnan, Zhejiang [India, Indonesia, Japan (Ryukyu Islands), Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam; Australia, Pacific islands].