Actaea racemosa, the black cohosh, black bugbane, black snakeroot, or fairy candle, is a species of flowering plant of the familyRanunculaceae. It is native to eastern North America from the extreme south of Ontario to central Georgia, and west to Missouri and Arkansas. It grows in a variety of woodland habitats, and is often found in small woodland openings. The roots and rhizomes were used in traditional medicine by Native Americans. Although its extracts are manufactured as herbal medicines and dietary supplements, black cohosh is not well-studied or recommended for safe and effective use in treating menopause symptoms or any disease.
Description
Black cohosh is a smooth herbaceousperennial plant that produces large, compound leaves from an underground rhizome, reaching a height of. The basal leaves are up to long and broad, forming repeated sets of three leaflets having a coarsely toothed margin. The flowers are produced in late spring and early summer on a tall stem, tall, forming racemes up to long. The flowers have no petals or sepals, and consist of tight clusters of 55–110 white, long stamens surrounding a white stigma. The flowers have a distinctly sweet, fetid smell that attracts flies, gnats, and beetles. The fruit is a dry follicle long, with one carpel, containing several seeds.
Taxonomy
The plant species has a history of taxonomic uncertainty dating back to Carl Linnaeus, who—on the basis of morphological characteristics of the inflorescence and seeds—had placed the species into the genus Actaea. This designation was later revised by Thomas Nuttall reclassifying the species to the genus Cimicifuga. Nuttall's classification was based solely on the dry follicles produced by black cohosh, which are typical of species in Cimicifuga. However, recent data from morphological and genephylogeny analyses demonstrate that black cohosh is more closely related to species of the genus Actaea than to other Cimicifuga species. This has prompted the revision to Actaea racemosa as originally proposed by Linnaeus. Blue cohosh, despite its similar common name belongs to another family, the Berberidaceae, is not closely related to black cohosh, and may be unsafe if used together.
Cultivation
A. racemosa grows in dependably moist, fairly heavy soil. It bears tall tapering racemes of white midsummer flowers on wiry black-purple stems, whose mildly unpleasant, medicinal smell at close range gives it the common name "Bugbane". The drying seed heads stay handsome in the garden for many weeks. Its deeply cut leaves, burgundy colored in the variety "atropurpurea", add interest to gardens, wherever summer heat and drought do not make it die back, which make it a popular garden perennial. It has gained the Royal Horticultural Society's Award of Garden Merit.
Traditional medicine
used black cohosh to treat gynecological and other disorders. Following the arrival of European settlers in the U.S. who continued the use of black cohosh, the plant appeared in the U.S. Pharmacopoeia under the name "black snakeroot". In the 19th century, the root was used to treat snakebite, inflamed lungs, and pain from childbirth. Black cohosh is used as a dietary supplement marketed mainly to women for treating gynecological problems, but there is no high-quality scientific evidence to support such uses.
Safety and health concerns
Rigorous studies on the long-term safety of using black cohosh, and its safety as a traditional medicine or dietary supplement, have not been published, mainly because most black cohosh materials are harvested from the wild with lack of proper authentication and adulteration of commercial preparations by other plant species. High doses of black cohosh may cause nausea, dizziness, visual effects, a lower heart rate, and increased perspiration. Worldwide, some 83 cases of liver damage, including hepatitis, liver failure, and elevated liver enzymes, have been associated with using black cohosh, although a cause-and-effect relationship remains undefined. Women have taken black cohosh without reporting adverse health effects, and a meta-analysis of clinical trials found no evidence that black cohosh preparations had adverse effects on liver function. According to Cancer Research UK: "Doctors are worried that using black cohosh long term may cause thickening of the womb lining. This could lead to an increased risk of womb cancer." They also caution that people with liver problems should not take it as it can damage the liver, although a 2011 meta-analysis of research evidence suggested this concern may be unfounded. In 2007, the Australian Government warned that black cohosh may cause liver damage, although rarely, and should not be used without medical supervision. Other studies concluded that liver damage from use of black cohosh is unlikely.
Phytochemicals
Black cohosh contains diverse phytochemicals, such as polyphenols and estrogen-like compounds implicated in effects of black cohosh extracts on hot flashes in menopausal women, although there is no effect confirmed by high-quality clinical research.
