Rugelia nudicaulis, the sole species of the genus Rugelia, blooms in summer. It is a wildflower endemic to higher elevations in the Great Smoky Mountains. It is a rare species in Tennessee. Genetic diversity in this plant, assessed using allozymes, is so low that the species may not survive changing environmental conditions. Both the scientific name and the common names honor Ferdinand Rugel, a botanist and plant collector who collected plant specimens throughout the southeastern United States during the period 1840–1848.