This unusual shrub is restricted to the central and southern Appalachians; the genus is known elsewhere only from one species in the Sino-Himalayan region (FNA 12). It is a semi-parasite on the roots of a wide range of woody species (Leopold & Muller 1983). Coder (2011) has compiled a popular summary of the species, with notes on the toxicity of its large green drupes, which may be dispersed by deer or other mammals. Deer are also reported to browse much on foliage, but plants recover well from spreading rhizomes. Toxins include oxalates and diverse thionins, which are proteins that can break down cell membranes in mammals.