The TENN vascular collection has a strong emphasis on widespread and/or temperate taxa. Even though the collection houses representative specimens of the world's flora, it is unique in having the largest collection of specimens from the state of Tennessee, the historical collections documenting the flora of the Great Smoky Mountains National Park (a World Biosphere Reserve), and the large, general collection from throughout the southern Appalachians. Significant and representative collections are also present from the remainder of the U. S., including Alaska, Central and South America, and Afro-Eurasia. The pteridophyte collection is more cosmopolitan than the rest of the vascular plant collection due, in large part, to the collecting and exchange of A. M. Evans and A. J. Sharp.