This is widespread in eastern states, except on the southeastern Coastal Plain, much of the Appalachian Plateaus, and much of the glacial till plain in Ohio (K). It occurs in mesic to subxeric woods on rocky base-rich soils. Despite some ancient medicinal uses of this species (Moerman 1986), there has been little recent publication on the chemistry (Kuzmanov & Dutschewska 1982). Reportedly, 2n = 14, 28 and 42, with 42 predominating (Soza et al. 2013). T, dioicum is indeed strictly dioecious, and part of a dioecious clade of largely North American species (Soze at al. 2012).