Common Name: Black Cohosh

General Information

Actaea racemosa is a herbaceous perennial plant producing one or more leafy stems from a thick rootstock. It can grow up to 250cm tall, but is more commonly within the range 120 - 180cm[, ].
The plant is a popular herbal remedy with a long history of medicinal use in N. America. It is often harvested from the wild for local use and for trade. A very ornamental species, that is often grown in larger gardens[].

Known Hazards

The plant is poisonous in large doses[]. Large doses irritate nerve centres and may cause abortion[].

Botanical References

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Range

Eastern N. America - Ontario to Massachusetts, south to Missouri and Georgia

Habitat

Moist, mixed deciduous forests, wooded slopes, ravines, creek margins, thickets, moist meadowlands, forest margins, and especially mountainous terrain from sea level to 1,500 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	1.50 m
Cultivation Status	Ornamental, Wild

Cultivation Details

Plants are hardy to at least -20°c[].
Prefers a moist humus rich soil and some shade, tolerating deep shade[, , , ]. Grows well in dappled shade[, , ]. Succeeds in ordinary garden soil[] and tolerates drier soils,[]. Foliage tends to scorch and otherwise depreciate if soils are allowed to dry out[]. Dislikes exposure to strong winds[].
The flowers have an unusual, slightly unpleasant smell[] which is thought to repel insects[]. Plants grow and flower well in Britain, though they seldom if ever ripen their seed[].
A greedy plant, inhibiting the growth of nearby plants, especially legumes[].

Edible Uses

Leaves - cooked[]. Some caution is advised, see the notes above on toxicity.

Medicinal

The root of this plant is toxic in overdose, it should be used with caution and be completely avoided by pregnant women[]. See also the notes above on toxicity.

Black cohosh is a traditional remedy of the North American Indians where it was used mainly to treat women's problems, especially painful periods and problems associated with the menopause[]. A popular and widely used herbal remedy, it is effective in the treatment of a range of diseases[].
At least some of the medically active ingredients are not soluble in water so a tincture of the root is normally used[].
The root is alterative, antidote, antirheumatic, antispasmodic, astringent, cardiotonic, diaphoretic, diuretic, emmenagogue, expectorant, hypnotic, sedative, tonic and vasodilator[, , , , , , , ]. It is used in the treatment of rheumatism, as a sedative and an emmenagogue[]. It is traditionally important in the treatment of women's complaints, acting specifically on the uterus where it eases uterine cramps and has been used to help in childbirth[, ]. The root is also hypoglycaemic, sedative and anti-inflammatory[]. Used in conjunction with St. John's Wort (Hypericum perforatum) it is 78% effective in treating hot flushes and other menopausal problems[]. An extract of the root has been shown to strengthen the male reproductive organ in rats[].
The root contains salicylic acid, which makes it of value in the treatment of various rheumatic problems - it is particularly effective in the acute stage of rheumatoid arthritis, sciatica and chorea[]. Its sedative action makes it useful for treating a range of other complaints including tinnitus and high blood pressure[].
The roots are used to make a homeopathic remedy[]. This is used mainly for women, especially during pregnancy[].
The root is harvested in the autumn as the leaves die down, then cut into pieces and dried[].

Research has shown that the root has oestrogenic activity and is thought to reduce levels of pituitary luteinizing hormone, thereby decreasing the ovaries production of progesterone[, ].

Other Uses

Both the growing and the dried plant can be used to repel bugs and fleas[].

Propagation

Seed - best sown as soon as it is ripe in a cold frame[]. Only just cover the seed. It germinates in 1 - 12 months or even longer at 15°c[]. The seed does not store well and soon loses its viability[], stored seed may germinate better if given 6 - 8 weeks warm stratification at 15°c and then 8 weeks cold stratification[]. Prick out the young seedlings into individual pots when they are large enough to handle and grow them on in a frame for their first winter. Plant out in late spring or early summer[].
Division in spring or autumn[]. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the summer or following spring.