Herbs , perennial, from hard, knotted, long-lived rhizomes. Leaves basal and cauline, compound, petiolate with basal wings clasping stem; cauline leaves alternate. Leaf blade 1-3-ternately compound; leaflets ovate-lanceolate to broadly obovate or orbiculate, 2-5-lobed, lobe margins toothed or shallow to deeply incised. Inflorescences terminal, many-flowered panicles of racemelike branches [spikes in Asian spp.], 7-60 cm; bracts 1 or 3, alternate, subtending pedicel (pedicels bracteolate in C . americana ), not forming involucre. Flowers bisexual [unisexual], radially symmetric; sepals not persistent in fruit, (2-)4-5(-6), greenish white or cream to greenish yellow, sometimes pinkish or tinged with red, plane or ± concave, ovate to obovate, 3-6 mm; petals 0-8, distinct, white or yellowish, plane, apex 2-cleft [entire], sometimes clawed, 3-6 mm; nectariferous area sometimes present; stamens 20-110; filaments filiform [flattened]; staminodes absent between stamens and pistils; pistils 1-8, simple; ovules 4-15 per pistil; style present. Fruits follicles, usually aggregate, sessile or stipitate, ovoid to obovoid, weakly to strongly compressed, sides not prominently veined; beak terminal, straight or hooked at tip, 0.5-2.5 mm. Seeds pale brown to reddish or purplish brown, angled or laterally compressed, hemispheric, lenticular, or cylindric, smooth, slightly ridged, verrucose, or densely scaly. x = 8. Cimicifuga may be divided into two natural groups: those with seeds scaly and those with seeds lacking scales or nearly so. Cimicifuga racemosa and C . elata of North America, with scaleless seeds, are most closely related to C . biternata (Siebold & Zuccarini) Miquel and C . japonica (Thunberg) Sprengel of Asia. Four or five species of Cimicifuga are cultivated as ornamentals, and at least five named cultivars have been developed.
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 4-5, petaloid, very convex, caducous; pet none; stamens very numerous, with long, white filaments and rounded or obovoid anthers, a few of the outermost usually transformed into expanded, 2-horned staminodes; pistils 1 or more; follicles several-seeded; tall perennial poisonous herbs with few, large, commonly basally disposed, ternately or pinnately compound or decompound lvs, broad lfls, and erect, elongate, many-fld racemes or panicles. 20, N. Hemisphere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.