Many Phellodon species are known from the southeastern United States, where they have been extensively researched. According to Baird and colleagues, there are nine distinct Phellodon species from Great Smoky Mountains and the surrounding southern Appalachian Mountains. Three additional species from this area, P. mississippiensis, P. brunneo-olivaceus, and P. fuligineoalbus were added to the genus in 2013-14.