Large annuals or biennials, glabrous; stems 60-200 cm tall, erect, simple or branched apically. Lower cauline leaves glabrous; oblong to lanceolate, 13-25×1.5-11 cm, apex acuminate, sessile or short petiolate, margins entire or usually pinnately incised or parted, segments of 2-4 pairs, acute to acuminate, upper surface green, lower surface glaucous; medium cauline leaves 10-24 cm long, linear-lanceolate, undivided, apex acuminate, base narrowly attenuate to partly clasping (f. indivisa) or oblong and deeply pinnatifid, segments remote, acuminate, entire or laciniate (f. runcinata); upper cauline leaves gradually smaller, becoming linear. Inflorescence a narrow cylindric panicle, 20-40 cm tall. Heads ca. 2 cm across; peduncle 10-25 mm long, erect. Involucre cylindric, 10-13×5-6 mm, bracts glabrous, purple, outer ones ovate, 2-3 mm long, inner ones ovate-lanceolate, innermost bracts 8, lanceolate. Florets 21-27, light yellow, 12-13×2 mm. Achenes elliptic, flat, black, 4-4.5×2.3 mm; beak 1-1.5 mm long, 1-ribbed on each side. Pappus white, 7-8 mm long. Chromosome number, 2n = 18 (Peng & Hsu, 1978).

TAIPEI: Yangmingshan, Peng 13518; Keelungyu, Peng 14095. ILAN: Wuchieh, Wang 1498. TAOYUAN: Fuhsing, Peng 14585. HSINCHU: Chupei, Peng 15227. MIAOLI: Kuanwu, Peng 8437. TAICHUNG: Takeng, Peng 9969. NANTOU: Wushe, Peng 10346; Tienchih, Ho 576. PINGTUNG: Lilungshan, Chen 883. TAITUNG: Haituan, Hsiao 1274; Lanyu Is., Peng 7650. HUALIEN: Hsiulin, Liu 380; Fuyuan, Peng 11644.

Malaysia, India, eastern Siberia, the Philippines, Japan and southern China. Taiwan, roadsides, sunny hillsides, from low to mid elevations, widespread and common.

This is a very variable species. Forma indivisa has been applied to plants with linear-lanceolate, undivided leaves; f. runcinata has been used for plants with oblong, deeply pinnatifid leaves with remote, acuminate, entire or laciniate segments.