• All Taxa Biodiversity Inventory;
  • Bangiophycidae;
  • Great Smoky Mountains;
  • Rhodospora;
  • subaerial

We recently discovered several populations of the red alga Rhodospora sordida Geitler in samples from seep walls in Tennessee. This species is thought to be an extremely rare alga. It was reported previously only from seep walls in Europe. The last published reports of the alga were made in the mid-1970s. A culture of the alga was made from one other site in North America (a rock wall in Arkansas) in 1977, but no publication accompanied that find. Since discovering the alga in summer 2004, we found a second population in a seep wall in northeast Ohio. We suspect that this species has a broader distribution than previously thought and has been overlooked or misidentified in past studies.