Japan Flora: Perennial short rhizorilatous herb, sometimes with short stolons; stems erect, usually simple, hollow, 70-120 cm. long, glabrous; cauline leaves petiolate, 10-20 cm. long, 5-10 cm. wide, pinnately divided, the terminal segments usually deltoid, acuminate, mucronate-toothed, the petioles wingless, upper leaves membranous, gradually smaller, lanceolate, broadly winged and pedolelike at base, nearly glabrous; panicle 15-30 cm. long, glabrous; heads about 1 cm. across, rather few-flowered; involucres 1-1.2 cm. long, the inner bracts 7-8, the outer ones much shorter than the inner; achenes lanceolate, nearly beakless, 3-3.5 mm. long, weakly ribbed; pappus white, about 6 mm. long. June-Aug.