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. The two species in North America are similar to each other vegetatively and differ primarily in flower and fruit characteristics.
Sep 3-5, obovate, petaloid, caducous; pet 4-10, deciduous, spatulate to obovate, clawed; stamens numerous, the elongate filaments mostly widened upwards; anthers oval; pistil 1; stigma broad, sessile, bilobed; fr 1- to several-seeded berry; poisonous, odoriferous perennial herbs with large, ternately 2-3 times compound lvs, sharply toothed lfls, and small, white fls in a dense, long-peduncled, terminal raceme. 5, circumboreal.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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