Erigeron bonariensis L
Annual or biennial herbs. Stems erect, 20-50 cm tall, branched upward, lateral shoots regularly overtopping main axis after appearance of heads, coarsely pilose and hirsute. Leaves densely arranged, pilose on both surfaces; basal leaves often withered at anthesis; lower leaves narrowly oblanceolate or oblong, 5-14×0.5-2 cm, apex acute, base attenuate, sessile, margins coarsely serrate-dentate or pinnatifid with up to 5 teeth or lobes on each side; upper leaves smaller, linear-lanceolate, nearly entire. Heads many, 4-6 mm long, 5-7 mm wide, pedunculate, in terminal racemose-panicles. Involucre urceolate, bracts in 3 or 4 series, linear lanceolate, acute, herbaceous, densely pubescent, subequal or outer ones shorter, inner bracts 3-4 mm long, outer bracts ca. 2 mm long. Outer florets numerous, in 6-7 marginal rows, corolla white, filiform-tubular, 2-2.2 mm long, ligule minute, obscure; style ca. 2.5 mm long, slightly longer than pappus. Central disc florets 12-20, corolla 3-3.5 mm long; upper part narrowly cylindric, longer than lower filiform part, 5-lobed, yellowish. Achenes oblong to oblanceolate, ca. 0.5-1 mm long, 0.2-0.3 mm thick, compressed, ribbed on both sides, minutely pubescent, pale umber. Pappus 1-seriate, united at base, tawny or reddish, capillary, bristles subequal, 3-3.5 mm long at maturity. Fl. Mar-Nov.
TAIPEI: Yangmingshan, Peng 13505; Shimen, Kuo 10952. TAOYUAN: Shalun, Peng 7716. HSINCHU: Lienhuassu, Peng 11501. MIAOLI: Tungsiao, Peng 11570. TAITUNG: Lanyu Is., Peng 10639. PINGTUNG: Hsiaoliuchiu, Huang 8250.
Native of South America. Taiwan, local in lowlands and littoral regions.