- Scientific name: Actaea racemosa L.
- Synonymy: Cimicifuga racemosa (L.)
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Endangered (MA Endangered Species Act)
Description
Black cohosh (Actaea racemosa) in flower. Photo credit: Arthur Haines, Native Plant Trust
Black cohosh (Actaea racemosa, formerly Cimicifuga racemosa) is a striking herbaceous perennial plant of the buttercup family (Ranunculaceae), with alternate, compound leaves and malodorous, wand-like, white inflorescences. Though indigenous to rich woodlands, black cohosh is also a common garden and herbal medicinal plant, and goes by the other common names black snakeroot, squawroot, and bugbane.
The leaves of black cohosh are 15-60 cm (~6-23 in) in length, smooth, and two to three times “ternately” (i.e., divided in three) compound, with 20-70 toothed leaflets. The flowering stem can be quite tall, reaching up to 2.5 m (~8 ft) in height. The inflorescence is usually branched, with several slender racemes of fetid, small, white flowers. Blooming starts at the base of the raceme and works to the top over the summer. Individual flowers do not have petals, and the small sepals fall off early. The flowers appear as a mass of stamens with white filaments 5-10 mm long (0.2-0.4 in), topped by rounded white anthers surrounding a single pistil. The fruit is a thick-walled, oval follicle, 5-10 mm (0.2-0.4 in) in size.
The leaves of black cohosh resemble those of red baneberry (Actaea rubra) and white baneberry (Actaea pachypoda). Like black cohosh, baneberries are known from rich woodlands and have compound leaves with toothed leaflets, but they are typically much smaller plants. The most distinguishing characters are the inflorescence and the fruit; in baneberries, the inflorescence is an unbranched raceme, and the fruit are berries, not follicles.
Black cohosh leaves. Photograph by Skye van der Laan.
Close-up of flowers. Photograph by Skye van der Laan.
Life cycle and behavior
Black cohosh is a slow-growing perennial species which has indeterminate blooms from late June through early August. Many insects are attracted by the fetid small of the flowers and collect pollen as well as transport it from flower to flower. Pollinators include bumble bees, sweat bees, flies, butterflies and small beetles. Follicles split open along one side in the fall to release small half-round flattened seeds. The small dark brown seeds are spread primarily through wind and gravity.
The seed requires rich moist soil to germinate, and periods of cold and warm moist stratification. They may take more than a year to germinate. Seed does not remain viable in the seed bank for long periods of time. Expansion of populations is primarily from mature plants spreading slowly by short rhizomes underground. Most populations in Massachusetts have few young plants.
Population status
Black cohosh is listed under the Massachusetts Endangered Species Act as Endangered. All listed species are protected from killing, collecting, possessing, or sale and from activities that would destroy habitat and thus directly or indirectly cause mortality or disrupt critical behaviors. Black Cohosh is currently known from Berkshire and Franklin Counties, and is historically known from Hampden, Hampshire, and Worcester Counties. The Massachusetts Natural Heritage & Endangered Species Program database has 7 records. Only 4 of these records have been observed within the last 25 years.
Distribution and abundance
Black cohosh is indigenous to eastern North America from Massachusetts and New York, south to Mississippi, Alabama, and Georgia, and west to Ontario, Michigan, Iowa, Missouri and Arkansas.
Only historic occurrences are known from Michigan and Iowa. It has been introduced in Maine and Quebec. It is considered critically imperiled in Massachusetts and Mississippi, imperiled in Illinois and Ontario. In most states where it is known, it is considered apparently secure, secure or hasn’t been ranked.
Distribution in Massachusetts
1999-2024
Based on records in the Natural Heritage Database
Habitat
In Massachusetts, black cohosh inhabits rich deciduous forests with moist alkaline soils. Associated canopy species include sugar maple (Acer saccharum), red maple (A. rubrum), red oak (Quercus rubra), eastern hemlock (Tsuga canadensis), and white ash (Fraxinus americana). Subcanopy and understory woody plants include hazelnut (Corylus americana), ironwood (Carpinus caroliniana), maple-leaved viburnum (Viburnum acerifolium), witch-hazel (Hamamelis virginiana), and spicebush (Lindera benzoin). Associated herbs include lady fern (Athyrium filix-femina), sensitive fern (Onoclea sensibilis), Christmas fern (Polystichum acrostichoides), wood ferns (Dryopteris spp.), wild geranium (Geranium maculatum), and blue cohosh (Caulophyllum spp.)
Healthy habitats are vital for supporting native wildlife and plants. Explore habitats and learn about conservation and restoration in Massachusetts.
Photo credit: Adam Kohl
Threats
Potential threats include competition from invasive species, physical damage from logging, motorized vehicles, and deer browse. A primary threat to this species is competition from exotic invasive species, such as Japanese barberry (Berberis thunbergii), Asiatic bittersweet (Celastrus orbiculatus), garlic mustard (Alliaria petiolata), and Morrow’s honeysuckle (Lonicera morrowii). At least at one site, the forest canopy is changing significantly from emerald ash borer (Agrilus planipennis) killing mature ash trees; the impact of this on black cohosh is not known. Overall, it is threatened by habitat degradation of eastern forests. Although not likely to be a primary concern in Massachusetts, it continues to be threatened by illegal collection in wild populations for the medicinal plant industry.
Conservation
Black cohosh populations are typically long-lived perennials and should be monitored periodically every 5 to 10 years to assess threats and determine if there are management needs. The best time to monitor is when the species is in bloom during July. Surveyors are encouraged to search for immature plants as well as flowering ones.
Management
Though black cohosh is vigorous in higher light conditions, increases in light and soil disturbance (e.g., due to tree harvest) can increase the vigor and competitive edge of exotic plants. Plans for tree removal or other projects in or near black cohosh habitat that increase light and disturb soil should include strategies to reduce sources of invasive plant introduction (e.g., contaminated machinery) and their spread. Black cohosh plants in deep shade that are not flowering might benefit from some light canopy pruning. Motorized vehicle access to or through black cohosh habitat should be prohibited. All active management of state-listed plant populations (including invasive species removal) is subject to review under the Massachusetts Endangered Species Act and should be planned in close consultation with the MassWildlife’s Natural Heritage and Endangered Species Program.
Research needs
Research is needed to determine minimum viable populations and best methods to increase the populations in Massachusetts. Monitoring across the species range has indicated that there are low levels of viable seed production, and low seedling survival.
References
Gleason, Henry A., and Arthur Cronquist. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, Second Edition. Bronx, NY: The New York Botanical Garden, 1991.
Haines, A. 2011. Flora Novae Angliae – a Manual for the Identification of Native and Naturalized Higher Vascular Plants of New England. New England Wildflower Society, Yale Univ. Press, New Haven, CT.
NatureServe. 2026. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. Accessed: 3/19/2026.
POWO (2025). Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; https://powo.science.kew.org/ Accessed: 6/9/2025.
Small, Christine J. and James L. Chamberlain. 2018. “Experimental harvest and regrowth in Appalachian black cohosh (Actaea racemosa, Ranunculaceae) populations: Implications for sustainable management of a medicinal forest herb.” Journal of the Torrey Botanical Society 145(2): 109-120.
Weakley, A.S. 2020. Flora of the southeastern United States. University of North Carolina Herbarium, North Carolina Botanical Garden, Chapel Hill, NC.
Contact
| Date published: | April 7, 2025 |
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| Last updated: | April 30, 2026 |