Conyza riparia Blume
Perennial undershrub or shrubs, scandent; branches elongated, to 4-6 m long. Stems woody 2-3 cm in diam., terete, striate, glabrate or sparsely puberulous particularly on inflorescence axes and on younger parts. Cauline leaves thick, oblong, 9-11×2.5-4 cm, margins remotely mucronulate or mucronulate-denticulate, glabrate or minutely pilose on both surfaces, apex short acuminate, base obtuse to cuneate, veins 5 or 6 pairs. Heads hemispheric, 10-15 mm across, 12-13 mm long, in terminal and axillary lax panicles. Involucral bracts in 3 or 4 series, usually distinctly purple tipped; outer bracts shorter, linear-lanceolate, 2-4×1 mm, with multicellular hairs; inner bracts linear-lanceolate, 8-9×0.9 mm, ciliate. Receptacle flat, 6-7 mm across, with white, multicellular hairs. Corollas yellow, tubular; bisexual florets 9-10 mm long with 5 triangular lobes, lobes with sessile glands and multicellular hairs; outer florets 8-9 mm long, 3- or 4-lobed. Achenes oblong to cylindric, 1.2-1.4×0.5 mm, 10-ribbed, sparsely hirsute. Pappus white, 5-6 mm long. Chromosome number, 2n = 16 (Peng & Hsu, 1978).
TAIPEI: Huangtitien, Chou 594; Nankangshan, Peng 12261; Keelung, Chitu, Peng 10257. ILAN: Wushihpi, Lin 45; Taipingshan, Peng 10320. TAOYUAN: Fuhsing, Peng 10291. HSINCHU: Chutung, Peng 8632; Kuanhsi, Leu 1648. MIAOLI: Shihtoushan, Chang 9468. TAICHUNG: Kukuan, Leu 1528; Fengyuan, Peng 12188. NANTOU: Shuili, Peng 9047; Luku, Ho 770. YUNLIN: Kukeng, Ou s. n. 1981. CHIAYI: Chiehtung, Peng 8882; Fanlu, Peng 10228. TAINAN: Tsengwen Reservoir, Chen 499; Hsinying, Sen s. n. 1943. KAOHSIUNG: Shanping, Huang 4909; Liukuei, Peng 11243. PINGTUNG: Wutai, Peng 10228; Tahanshan, Yang 24663. HUALIEN: Taroko, Peng 13025; Lintienshan, Peng 2608.
Southern Asia, Japan, and southern China. Taiwan, widespread and common, in thickets and sunny situations on hillsides at low elevations.