Fomes fasciatus, common name the Southern Clam Shell, is a pathogenic white rot fungus in the family Polyporaceae.

F. fasciatus is in the same Genus as the better known Horse Hoof or Tinder Conk fungus Fomes fomentarius, which was discovered with the 5,000 year old body of Otzi the Iceman in the Italian Alps.

[5][circular reference] It has a similar morphology to F. fomentarius and has likely been confused in identifications given that both species overlap in physical features and variances.

[7] Both are economically important wood-decay fungi found on various hardwood trees and both produce large, woody, clam to hoof shaped conks that contain trimitic hyphae.

[8] In North America the fungus is commonly found on host trees like hackberry, hickory, maple, and oak but has been recorded on at least ten genera worldwide where it contributes to the loss of commercially viable wood.

[7] Fomes fasciatus has also been researched as a potential cheap biosorbent of heavy metals due to its common occurrence and lack of current economic use.