Family: Barberry (Berberidaceae)
Height: To 3’ (90 cm)
Flowering: April - June
Habitat: Shady, Moist, Deciduous Woods
Toxicity: Leaves and Seeds are Poisonous
Cohosh is believed to be a New England Algonquin name describing this and other flowers of the Barberry (Berberidaceae) family including Black (Cimicifuga racemosa) and White Cohosh (Actaea alba). Cohosh is derived from Co-os− meaning “pine tree” probably referring to the spiked appearance of most Cohosh plants. Blue alludes to the color of the fruit produced by the mature plant, which is a dark blue-green color.
The scientific name, Caulophyllum thalictroides, describes the leaves of the plant that resemble Meadow Rue. Caulophyllum is derived from kaulos and phylum, which means stem and leaves. The compound leaf of Blue Cohosh is almost without a true petiole. The leaf appears to connect directly to the stem independent of a leaf stalk rationalizing the genus name (“leaf-stem”). Thalictroides alludes to the foliage of the plant which resembles the leaves of Early (T. dioicum) or Tall Meadow Rue (T. dasycarpum), both members of the Thalictrum genus.
Blueberry Root: Refers to the deeply colored fruit produced by the plant at maturity.
Blue or Yellow Ginseng, Seneca Root: Blue Cohosh is occasionally mistaken for both Ginseng and Seneca owing to the smell and taste of its roots.
Papoose Root, Squawroot: Early settlers applied this name after seeing that Native Americans employed the roots for a variety of medical purposes.
Each of the petals of the delicate green flower contains nectar glands that are visited by early spring bumblebees and flies. Both species of insects are also key pollinators for the plant. Because the male and female parts of the flower mature at different times the plant ensures cross-pollination.
Upon fertilization, the ovary ripens forming a blue “fruit” that is arguably not a fruit at all. The berries are actually seeds surrounded by a dark blue fleshy seed coat that protects the brown seed inside. Because the ovarian wall is shed during the early phases of seed development, the fruit is actually a naked seed. The exposure of the seeds is an unusual condition for flowering plants. By bearing its seeds openly, Blue Cohosh is vulnerable to predators that would eat the seeds. The plant counteracts this vulnerability with the toxicity of its seeds. Blue Cohosh seeds are poisonous to many species including humans.
Native Americans and pioneers found many uses for Blue Cohosh by way of medical remedies. A root-infused tea was used to treat a variety of medical ailments among many different tribes. The Meskwaki Indians used it for treating genitourinary disorders. The Omaha tribe used the tea to break a fever.
Pioneers used the plant in a treatment for rheumatism, epilepsy, colic, and many other ailments.
The flower was found to be an effective parturifacient, used to facilitate childbirth. For a week or two before the expected date of delivery, pregnant women would drink a tea infused with powdered Blue Cohosh roots. The tea was believed to induce a rapid and painless labor. This property was attributed to the glycoside caulosaponin produced by Blue Cohosh9. Caulosaponin constricts the coronary blood vessels which has negative effects on the heart, damaging the cardiac muscle. If the tea was drunk any earlier, it often induced abortion and was cited as the source of many miscarriages.
Blue Cohosh was also considered a powerful emmenagogue. Women of various tribes would use a root infused tea to suppress heavy menstrual flow, relieve cramps, and promote dropsical discharges.
Experimental evidence exists supporting the antispasmodic and diuretic properties of Blue Cohosh roots6. When used in various herbal treatments it can suppress spasms, convulsions, and other nervous derangements6. Modern herbalists use the plant roots today to treat rheumatism and bronchitis.
Caution should be taken when consuming any part of Blue Cohosh plants. The leaves and seeds contain methylcytisine, an alkaloid, as well as other glycosides that are poisonous9. Experiments show that methylcytisine action mimics the effects of nicotine when taken internally6. The compound elevates blood pressure and stimulates both respiration and intestinal motility causing severe stomach pain and shortness of breath9. Children who mistake the flesh covered seeds for blueberries have been poisoned by the toxic effects of Blue Cohosh6. In general, the plant should not be consumed unless under strict supervision.
Some reports say that the seeds can be roasted and used as a coffee substitute. The roasting process supposedly removes the toxic elements of the seeds.