The park is home to three federally listed threatened (T) and endangered (E) plant species: spreading avens (E), Virginia spiraea (T), and rock gnome lichen (E), the latter being part fungus. View a listing of federally Threatened and Endangered Species. Over 300 additional species of native vascular plants are considered rare, meaning they are generally found in small populations or have five or fewer occurrences within the park. Once one of the park's most common trees, the American chestnut is almost gone from the park landscape. Also considered rare are nearly 200 of the 450 non-vascular plants. A total of 76 species of park plants are listed as threatened or endangered in the states of Tennessee and North Carolina. Some plants are rare because they are being poached.