Annual; stems 17-50 mm long, branched at base, glabrous. Leaves glabrous; radical leaves linear-lanceolate, 7-17×0.5-1.5 cm, sessile, sagittate, margins entire, slightly mucronulate to pinnately dissected, apex acuminate to acute or obtuse, base narrowed; median cauline leaves lanceolate, 6-17×1-1.7 cm, margins entire or slightly mucronate, upper leaves few, lanceolate, base auriculate, sessile. Heads nodding after flowering, in false umbels; peduncle slender, 6-28 mm long, bracteoles 1 or 2, 0.5 mm long. Involucre cylindric, 5-7×2.5-3.5 mm; outer bracts few, ovate, 0.5 mm long; inner bracts 8, ovate-lanceolate, margins transparent, apex corniculate or not. Florets 20-25; corolla 8-8.5×1 mm. Achenes slightly compressed, 3.5-4×0.7-0.5 mm, 10-angled; beak slender, 1 mm long. Pappus white, 3.5-4 mm long, persistent.

HSINCHU: Hengshan, Peng 13667. MIAOLI: Yuanli, Peng 10570. TAICHUNG: Chingshui, Peng 4479. CHIAYI: Shuishang, Yen s. n. 1989.

Southern and southeastern Asia, Japan, Korea and China. Taiwan, dry to moist paddy fields and other moist places.

Ixeris polycephala is highly variable in leaf shape. Plants with pectinate-pinnatifid leaves were given infraspecific ranks as f. dissecta or var. dissecta.