What is "rugelia"

Rugelia nudicaulis, Rugel's Indian plantain or Rugels ragwort, is the sole species of the genus Rugelia which blooms in summer, is a wildflower endemic to higher elevations in the Great Smoky Mountains. It is a rare species in Tennessee. It was first placed in the genus Senecio, then moved to Cacalia and finally placed in a genus of its own, Rugelia. Genetic diversity in this plant, assessed using allozymes, is so low that the species may not survive changing environmental conditions.