败酱叶菊芹 bai jiang ye ju qin

Senecio valerianifolius Link ex Sprengel, Syst. Veg. 3: 565. 1826 ["valerianaefolius"].

Herbs, annual. Stems erect, 50-100 cm tall, simple or branched in upper part, striate, subglabrous. Leaves long petiolate; petiole narrowly winged; blade oblong to elliptic, both surfaces glabrous, pinnately veined, base cuneate, margin irregularly double serrate or pinnatipartite; lobes 12-16, lanceolate, acuminate, serrate to irregularly lobed, or rarely shallowly lobed, apex acute or acuminate; upper leaves similar to median leaves but smaller. Capitula numerous, erect or pendulous, in terminal and upper axillary dense corymbose panicles, ca. 10 × 3 mm, with linear bracteoles. Involucres cylindric-campanulate; phyllaries uniseriate, 12-14(-16), linear, 7-8 × 0.5-0.75 mm, glabrous or sparsely puberulent, 4- or 5-veined, apically acute or acuminate. Florets numerous, yellowish purplish; outer florets uni- or biseriate, corolla filiform, apically 5-denticulate; central florets minutely tubular-funnelform, 7-8 mm, rather longer and broader than outer ones, 5-denticulate, apically glandular thickened. Style branches with conical appendages. Achenes cylindric, 2.5-3.5 mm, glabrous or puberulent, 10-12-ribbed. Pappus reddish, as long as florets. Fl. year-round. 2n = 40.

Roadsides, field margins; ca. 1700 m. Guangdong, Hainan, Taiwan [native to tropical America; a pantropical weed].