Leaves of nonflowering shoots 2.5-9 dm. Leaf blades 13-53 cm diam. Flowering shoots 6-12 dm; leaves alternate, unequal in size; proximal leaf petioles 10-18 cm, blades 17-46 × 23-56 cm; distal leaf petioles 3-15 cm, blades 10-38 × 15-51 cm. Leaf blade divided at apex and base into 2 parts, each part 5-9-lobed, lobes broadly acuminate, abaxially sparsely pubescent with unicellular hairs. Inflorescences cymose, glabrous; peduncle 0.2-4 cm; pedicel 0.7-3.5 cm; peduncle and pedicel turning red at fruit maturity. Flowers 7-70 (or more); outer sepals 1.7-4.5 × 0.4 mm; inner sepals 2.5-6 × 3.5-4 mm; outer petals narrowly obovate, 9-11 × 4.5-6 mm; inner petals elliptic to obovate, 10-13×6-7 mm; stamens 3-4 mm; filaments 1-2 mm; anthers 2 × 1 mm; ovaries ellipsoid, 3-5 × 1.5-2.5 mm; stigma 0.5-1 mm. Berries 6-13 × 4-11 mm. Seeds 2-4, 4-7 × 2-5 mm, abaxially rounded, adaxially flattened to concave. 2 n = 12.
Flowering late spring, fruiting summer. Forming dense colonies on moist slopes in mixed deciduous forests, in seepages, or along streams; 800-1700 m; Ga., N.C., S.C., Tenn., Va.
Diphylleia cymosa is endemic to the Blue Ridge Mountains of the southern Appalachians. It is occasionally grown in woodland gardens.
Cherokee Indians are reported to have used D . cymosa to treat a variety of ailments and as a disinfectant (D. E. Moerman 1986).
Basal lvs long-petioled, the blade 2-5 dm wide, 2-cleft, radially many-lobed and sharply dentate; cauline lvs a little smaller, similarly cleft; cyme 5-10 cm wide; fls many, white, 15 mm wide; fr blue, 1 cm, on red pedicels 1-3 cm; 2n=12. Cool mt. woods; Blue Ridge prov. from Va. to Ga. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.