9. Actaea Linnaeus, Sp. Pl. 1: 504. 1753; Gen. Pl. ed. 5, 222, 1754.
Baneberry, necklaceweed, cohosh, actée [Greek, aktea, ancient name for the elder, probably for leaf similarity]
Bruce A. Ford
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.
Species ca. 8 (2 in the flora): temperate to cool forests throughout Northern Hemisphere.
The two species in North America are similar to each other vegetatively and differ primarily in flower and fruit characteristics.
Hultén, E. 1971. The circumpolar plants. II. Dicotyledons. Kongl. Svenska Vetenskapsakad. Handl., ser. 4, 13: 1-463. Keener, C.S. 1977. Studies in the Ranunculaceae of the southeastern United States. VI. Miscellaneous genera. Sida 7: 1-12. Pellmyr, O. 1985. The pollination biology of Actaea pachypoda and A. rubra (including A. erythrocarpa) in northern Michigan and Finland. Bull. Torrey Bot. Club 112: 265-273.