. The flora of the region comprises two endemic monotypic families, Hydrastidaceae and Leitneriaceae, and is characterized by about a hundred of endemic genera (such as "Sanguinaria", "Leavenworthia", "Gillenia", "Neviusia", "Dionaea", "Yeatesia", "Pleea"). The degree of species endemism is very high, many species are Tertiary relicts, which survived the Wisconsin glaciation and are now concentrated in the Appalachians (esp. Blue Ridge Mountains) and the Ozarks