Aerial shoots (15-)20-80 cm, from caudices on rhizomes, caudices ascending, rhizomes ascending to horizontal. Basal leaves 1-5, simple, deeply divided; petiole 8-22(-37) cm; leaf blade orbiculate, 4-10 × 5-15(-20) cm, base sagittate to nearly truncate, margins serrate and incised on distal 1/3-1/2, apex acuminate, surfaces puberulous (more so abaxially); segments primarily 3, lanceolate to oblanceolate; lateral segments again 1×-lobed or -parted (proximal lobe occasionally lobed again); ultimate segments 10-30(-35) mm wide. Inflorescences 1(-3+)-flowered, rarely cymes; peduncle puberulous to villous, distally densely villous; involucral bracts 3 (secondary involucres with 2), remotely subtending flowers, (1-)2-tiered, simple, ±similar to basal leaves, broadly obtriangular, 3-cleft, 3-10 cm, bases broadly cuneate, connate, margins sharply, irregularly serrate and incised on distal 1/3-1/2, apex acuminate, surfaces puberulous, more so abaxially; segments 3, lanceolate to oblanceolate; lateral segments unlobed or 1×-lobed; ultimate lobes (8-)10-15(-20) mm wide. Flowers sepals (4-)5(-6), white, obovate, (8-)10-20(-25) × 5-15 mm, hairy or glabrous; stamens 80-100. Heads of achenes spheric to ovoid; pedicel 7.5-11.5 cm. Achenes body obovoid to ellipsoid, (2.5-)3-6 × 3.5-6 mm, winged, strigose or glabrate; beak straight, 2-6 mm, strigose, not plumose. |