1. Adenostemma lavenia (Linnaeus) Kuntze, Revis. Gen. Pl. 1: 304. 1891.
下田菊 xia tian ju
Herbs, annual, 30-100 cm tall. Stems erect, solitary, rigid, usually divaricately branched in upper part, white puberulent, glabrous in lower part. Leaves remote; basal leaves persistent or withered at anthesis; median leaves large; petiole narrowly winged, 0.5-4 cm; blade elliptic-lanceolate to elliptic or rhombic-elliptic, or broadly ovate to cordate, 4-12 × 2-5 cm, both surfaces sparsely puberulent or glabrescent, usually rather densely hairy on veins, base broadly or narrowly cuneate, margin crenate or incised, serrate, or doubly serrate, apex acute or obtuse; upper and lower leaves smaller, shortly petiolate. Capitula few, rarely many, small, in a lax or dense corymb or panicle; peduncle 0.8-3 cm, gray-white or ferruginous puberulent; involucre hemispheric, 4-5 × 6-8 mm, to 10 mm in diam. at fruiting; phyllaries 2-seriate, green, subequal, narrowly elliptic, thin, submembranous, outer phyllaries mostly connate, sparsely white villous, apex obtuse; corollas ca. 2.5 cm, viscid-glandular, pubescent. Achenes blackish brown when mature, oblanceolate, ca. 4 × 1 mm, glandular, sometimes densely tuberculate, contracted at base, apex obtuse; pappus elements clavate, ca. 4.1 mm, basally connate into a ring, fulvous viscid-glandular. Fl. and fr. Aug-Oct. 2n = 20.
Watersides, roadsides, forests and thickets on slopes, forest margins; 400-2300 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Nanhai Zhudao, Shaanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [India, Japan, Korea, ?Myanmar, Nepal, Philippines, Thailand; probably widespread throughout SE Asia, Australia].
This is an extremely variable and problematic taxon. Adenostemma lavenia is regarded by some authorities as distinct from A. tinctorium and A. viscosum, and to be endemic to Sri Lanka (cf. King & Robinson, Monogr. Syst. Bot. 22: 1-581. 1987), while others consider it to be pantropical.