Sp. Pl. 1: 504. 175
Gen. Pl. ed. 5, 222. 1754
Herbs, perennial, from caudices ca. 1 cm thick. Leaves cauline, alternate, petiolate. Leaf blade 1-3-ternately or -pinnately compound; leaflets ovate to narrowly elliptic, unlobed to 3-lobed, margins sharply cleft, irregularly dentate. Inflorescences terminal or axillary, 25(-more)-flowered racemes, 2-17 cm; bracts leaflike, sometimes present between leaves and inflorescence, bracteoles 1-2, at base of each pedicel, not forming involucre. Flowers bisexual, radially symmetric; sepals not persistent in fruit, 3-5, whitish green, plane, orbiculate, 2-4.5 mm; petals 4-10, distinct, cream colored, plane, spatulate to obovate, clawed, 2-4.5 mm; nectary absent; stamens 15-50; filaments filiform; staminodes absent between stamens and pistils; pistil 1, simple; ovules many per pistil; style very short or absent. Fruits berries, solitary, sessile, broadly ellipsoid to nearly globose, sides smooth; beak a wart, terminal, to 1 mm. Seeds dark brown to reddish brown, obconic to wedge-shaped, rugulose. x = 8.
Temperate to cool forests throughout Northern Hemisphere.
Species ca. 8 (2 in the flora).
The two species in North America are similar to each other vegetatively and differ primarily in flower and fruit characteristics.
|1||Pedicel in fruit bright red, stout, (0.7–)0.9–2.2(–3) mm diam., ± as thick as axis of raceme; stigma at anthesis as broad as or broader than ovary, 1.5–2.8 mm diam. in flower and fruit; petals truncate or cleft, often antherlike at apex; berries white, very rarely red.||Actaea pachypoda|
|1||Pedicel in fruit dull green or brown, slender, 0.3–0.7 mm diam., thinner than axis of raceme; stigma at anthesis narrower than ovary, 0.7–1.2 mm diam. in flower and fruit; petals acute or obtuse, not cleft or antherlike at apex; berries red or white.||Actaea rubra|