Caulophyllum is a small genus of perennial herbs in the family Berberidaceae. It is native to eastern Asia and eastern North America. These plants are distinctive spring wildflowers, which grow in moist, rich woodland, it is known for its large triple-compound leaf, and large blue, berry-like fruits. Unlike many spring wildflowers, it is not an ephemeral plant and persists throughout much of the summer. Common names for plants in this genus include Blue Cohosh, Squaw Root, and Papoose Root. As hinted at by its common names, this plant is well known as an alternative medicine for inducing childbirth and menstrual flow; it is also considered a poisonous plant.
In April or May, each mature stem bears a spike of flowers. Each flower has six petal-like sepals which range from greenish-yellow to purple. The different rates of maturity between the stamens and the pistil insures cross pollination. There are six fleshy nectar glands at the base of each sepal which attract pollinators. Each fertilized flower matures into a large (1 cm) deep-blue berry-like fruit which houses two bitter seeds. The large seeds are covered with a characteristic blue coat and the fruits remain on the plants until fall. Seed germination can take a few years and the seedlings are hypogeal, the cotyledons remaining underground after germination and seedling emergence, the seedlings need a few years of growth before they are large enough to flower.
Historically the root of Caulophyllum has been used as a medicine for: cancer, internal parasites, smooth muscle function, spasms, diuretic, menstruation, and childbirth. It is best known for the latter two uses. Various Native American tribes are also recorded as having used this plant for similar medicinal purposes. While no current widely marketed medicines are based on this plant, modern herbalists and practitioners of alternative medicine still utilize this plant as a natural therapy. Research on the medicinal potentials of this plant are ongoing.