Plant of the Week: Blue Cohosh (Caulophyllum thalictroides)

This early spring blooming woodland flower is not that showy for the garden, although I do like the texture and leaf/stem color and the blue berries in the fall.  It is mostly grown for it's medicinal purposes (more on that in a minute).  This is a 1 -3' tall plant that is unbranched and has a smooth stem that varies from light green to light purple. Non-flowering plants have a single compound leaf at the top of the stem.  Flowering plants have two compound leaves and each leave is subdivided into 9 subleaflets.  The flower clusters range from 5 - 30 individual 1/3" wide brownish to reddish-brown flowers with 6 petals.  A member of the Barberry family, this is a long-lived species which has both rhizomes and fibrous roots so it can form small colonies because it is somewhat difficult to grow from seed.  It likes dappled shade with very rich organic soils. The flowers are pollinated by various small flies, parasitoid wasps, and small bees.  The berries are toxic to humans and the foliage is also toxic to many mammals, including white-tailed deer, hence it is a plant that can be used where deer densities are high. The name cohosh comes from the Algonquin word meaning rough, which refers to the root. While this is not that showy of a plant in flower (it is showier with the bright blue berries - hence the seed is most likely dispersed by birds), what is fascinating about this plant is it use as a medicinal plant.  It has been used for starting labor and menstruation, constipation, stomach cramps, sore throat, hiccups and seizures. Unfortunately most of these claims are unverified by research. The established medical community generally considers blue cohosh to be unsafe to take for both children and adults. There is scientific evidence that it makes the uterus contract and should not be taken if pregnant or to aid in delivery and there have been cases reported that blue cohosh taken at the time of delivery may cause; 1) perinatal stroke, 2) acute myocardial infarction, profound congestive heart failure and shock and 3) severe multi-organ hypoxic injury. It makes chest pain (angina) and high blood pressure worse; it raises blood sugar in diabetics; makes diarrhea worse, and has a tendency to act like estrogen affecting breast cancer, ovarian cancer, uterine cancer, endometriosis, and uterine fibroids. The list of drug interactions is long and makes nictoine more addictive and harmful.  As with any herbal medicine, if you decide to use this, and it is widely available, you should consult your doctor prior to beginning a treatment regime.