Among these are&colon; tansy, pennyroyal, black cohosh, and the now-extinct silphium. Black cohosh has been shown to have no estrogenic effect "in vivo" or "in vitro". Additionally, black cohosh is being harvested from the wild for use as a dietary supplement. Native Americans used black cohosh to treat gynecological and other disorders. Flowers include painted trillium, small purple-fringed orchids, black cohosh, broad beech ferns. Common names for plants in this genus include blue cohosh, squaw root, and papoose root. Cress, foam flowers, blue cohosh, and occasionally orchids are found. Other studies concluded that liver damage from use of black cohosh is unlikely. Black cohosh has been implicated in a case of liver failure. During summer, ferns and blue cohosh grow in the shade.