Bull. Torrey Bot. Club 24: 561. 1897.
Stems 30-140 cm, glabrous. Leaves: petiole angled, 20-50 cm, proximally deeply grooved adaxially, densely pubescent in groove, otherwise glabrous or sparsely pubescent. Leaf-blade 1-2-ternately compound; leaflets 3-9 (-17); terminal leaflet of central segments broadly obovate, deeply 3-5-lobed, 9-30 × 9-25 cm, with 5-9 prominent veins arising basally, base deeply cordate, margins coarsely and irregularly dentate, apex sharply acuminate, surfaces abaxially with long, appressed, delicate hairs, adaxially glabrous; other leaflets 8-24 × 6-22 cm. Inflorescences erect panicles of 2-6 racemelike branches, terminal raceme 15-30 cm, puberulent to short-pubescent; bracts 3, subtending pedicel, central bract larger, lanceolate, 2 mm, lateral bracts ovate-deltate; pedicel to 5 mm, short-pubescent, bracteoles absent. Flowers: sepals 5, white; petals absent; stamens 35-65; filaments 3-5 mm; pistils 1 (-2), sessile, sparsely glandular; style short, straight or slightly recurved; stigma minute, 0.2-0.3 mm wide. Follicles 1 (-2), sessile, oblong, strongly compressed laterally, 8-20 mm, thin walled. Seeds reddish-brown, lenticular, covering of scales giving cylindric appearance, ca. 3 mm, covered with reddish-brown, membranous scales. 2n = 16.
Phenology: Flowering summer–fall (Aug–Oct).
Habitat: North-facing, limestone talus slopes and river bluffs, ravines, and coves, and along rivers and creeks
Elevation: 300-900 m
Ala., Ill., Ind., Ky., Tenn., Va.
In addition to being found in the Ridge and Valley Province of Tennessee and Virginia, Cimicifuga rubifolia has disjunct populations in Alabama, the lower Ohio River Valley, and in the middle Tennessee counties of Davidson, Montgomery, and Stewart.
The name Cimicifuga racemosa var. cordifolia has been misapplied to C. rubifolia. See discussion of C. cordifolia under C. americana.
"thin" is not a number.