[1] The species grows on the bark of decaying hardwood trees.

Its fruiting body is sessile, and ranges from 1 to 5 centimetres (1⁄2 to 2 in) wide.

[2] The surface of the fruiting body is dark brown or black and has a rough texture due to the high number of perithecia.

Species of Jackrogersella, Rosellinia, and Nemania have fewer bumps.

[2] Annulohypoxylon thouarsianum is most commonly found along the United States' West Coast, in the Eastern U.S., and in Mexico.