金腰箭 jin yao jian

Verbesina nodiflora Linnaeus, Cent. Pl. 1: 28. 1755.

Annuals, 10-80 cm tall. Stems erect or ascending, branched from bases or ± throughout. Leaves cauline, opposite, petiolate; blade ovate to elliptic, 3-10 × 2-5 cm, both surfaces ± scabrid, usually 3-veined, base cuneate to rounded, margin toothed. Capitula radiate, sessile or subsessile in axillary glomerules or capitula solitary; involucres cylindric to campanulate, 3-6 mm in diam.; phyllaries persistent, 2-5+, 1(or 2)-seriate, lanceolate, herbaceous to papery; receptacle convex; paleae linear-lanceolate, scarious, flat or weakly cupped at bases. Ray florets 2-9, 1- or 2-seriate, female, fertile; corollas yellowish, ca. 2 mm; lamina ovate to linear, 2-4 mm. Disk florets 4-12+, bisexual, fertile; corollas yellowish, tubes ca. 4 mm, ± equaling slightly enlarged cylindric throats, 4-lobed, orbicular-deltate. Fl. year-round. 2n = 40.

Fields, wastelands, roadsides. Guangdong, Hainan, Taiwan, Yunnan [pantropical weed of South American origin].