Black Cohosh

Scientific Name: Actaea racemosa. The species name, racemosa, refers to the fact that the flowers are in racemes. Racemes are long, unbranched flowering spikes with individual flowers borne on short stalks off the central stem in which flowers begin blooming from the bottom up.

Common Name: Black Cohosh. What do you think of the smell of these flowers? People often find it unpleasant and have used the plant to deter insects, giving it the name black bugbane. In fact, the genus Cimicifuga (a previous scientific name for this plant was Cimicifuga racemosa) is made up of two Latin words – Cimex, the genus of bed bugs, and fugare which means repel. Another name, black snakeroot, references the use of this plant to treat snakebites.¹ Having many common names can be confusing but it tells us a lot about the use of the plants!

Family: Ranunculaceae (Buttercup Family). Plants in the buttercup family usually have leaves that are divided (cut or lobed). The flowers are radially symmetric, have 3-6+ petal-like sepals (green, leaf-like structure surrounding the petals), up to 13 petals, and produce nectar. Fruits are often made up of lots of little separate fruitlets clustered together. Aside from many species of buttercup, some other well-known spring-blooming plants in this family include rue-anemone (Thalictrum thalictroides), round-lobed hepatica (Hepatica americana), and dwarf larkspur (Delphinium tricorne).²

Average Height: 3-7’

Description: A perennial plant that grows in colonies, spreading primarily through regrowth from underground horizontal stems. The alternate, compound leaves consist of three leaflets which are further divided. Each leaflet is roughly oval in shape, measures about 4” long and 3” wide, and is very toothed. Flowering stalks (called racemes – remember the species name is racemosa!) often exceed 1’ in length and are quite narrow and cylindrical. Numerous individual flowers are attached to the main stalk by short stems. Each white flower measures about ⅔”, has 24 long stamens and a single pistil. The flowering stalks mature from the bottom up, so you may find one-celled fruits with several seeds near the base of the stalk, blooming flowers in the middle, and flower buds near the top of the stalk.^2,3,4,5

Bloom time: May – Aug

Notes: Demand for black cohosh as an herbal medicine has led to significant harvesting of wild populations, leading to an estimated decline of 10-50% over the past 20 years. When not in bloom, Actaea racemosa may look similar to other species such as Actaea pachypoda, Actaea podocarpa, and Aruncus dioicus.⁴

Range: Found throughout most of Virginia, but absent or infrequent in parts of the Coastal Plain.⁴ Its range in North America extends from southern Ontario and New York south to Georgia and Alabama and west to Missouri and Arkansas.⁵

Geology/Soil: Typically found on nutrient-rich soils which include high levels of calcium, magnesium, and potassium.^2,4

Habitat: Most strongly associated with moist deciduous forests and forest coves and ravines, but can be found also in some dry forests. Particularly prevalent in rich cove forests and rich oak-hickory forests in the mountains.^2,4

Flora associations: Often found with a wide array of other species of rich forests such as blue cohosh (Caulophyllum thalictroides), large-flowered trillium (Trillium grandiflorum), common wild ginger (Asarum canadense), aniseroot (Osmorhiza longistylis), showy orchis (Galearis spectabilis), white ash (Fraxinus americana), basswood (Tilia spp.), and tulip-tree (Liriodendron tulipifera).⁶

Fauna associations: Many types of bees, flies, and beetles visit these flowers. The Appalachian azure butterfly (Celestrina neglectamajor) uses black cohosh as its host plant. The butterflies lay eggs on the plant and the caterpillars develop by eating it.³

Piedmont Discovery Center (PDC) did a study to document a previously unknown population of the Appalachian azure on Albemarle County property in the Ragged Mountains. In order to certify that this was indeed Celestrina neglectamajor and not the similar and more common spring azure (Celestrina ladon), PDC surveyed 181 Actaea racemosa plants, recording the color (yellow, green or maroon depending on the size) and length of all caterpillars and the number of eggs on each flowering stalk.

Human associations: Over time, people have found a variety of medicinal and other uses for Actaea racemosa. The Cherokee people make a tea to treat fever, colds, headaches, rheumatism, and female conditions. They also treat snakebite with it.^1,7,8 Similarly, the Haudenosaunee people use it for rheumatism, sore backs, and women’s health.⁸ European settlers learned to make compounds to treat smallpox and women’s ailments.¹ There continue to be a wide variety of herbal medicines based on black cohosh today, including ones for the treatment of menopausal symptoms.¹

We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!

1 Predny, Mary L.; De Angelis, Patricia; Chamberlain, James L. 2006. Black cohosh (Actaea racemosa): an annotated bibliography. Gen. Tech. Rep. SRS–97. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 99 p.

2 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, , pp. 827-831.

3 “Black Cohosh (Cimicifuga Racemosa).” Www.illinoiswildflowers.info, www.illinoiswildflowers.info/woodland/plants/black_cohosh.htm. Accessed 12 July 2024.

4 “Digital Atlas of the Virginia Flora | Actaea Racemosa L.” Www.vaplantatlas.org, www.vaplantatlas.org/index.php?do=plant&plant=2625&search=Search. Accessed 12 July 2024.

5 “NatureServe Explorer 2.0.” Explorer.natureserve.org, explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.154359/Actaea_racemosa.

6 “Low-Elevation Mesic Forests.” Www.dcr.virginia.gov, www.dcr.virginia.gov/natural-heritage/natural-communities/nctb. Accessed 12 July 2024.

7 “Black Cohosh (Actaea Racemosa).” My Cherokee Garden, 29 Sept. 2016, mycherokeegarden.com/2016/09/29/black-cohosh-actaea-racemosa/. Accessed 12 July 2024.

8 “BRIT – Native American Ethnobotany Database.” Naeb.brit.org, naeb.brit.org/uses/search/?string=actaea+racemosa. Accessed 12 July 2024.

Definitions:

Raceme: A long, unbranched flowering spike with individual flowers borne on short stalks off the central stem in which flowers begin blooming from the bottom up.

Sepal: A green, leaf-like structure surrounding the petals.