Protolog: TIMDAL, E., In: Nash et al.(ed.), Lichen flora of the greater Sonoran Desert region1: 499 (2002)
Locality: MEXICO, CHIHUAHUA: Barranca del Cobre, small, broad secondary valley within the canyon with pines (Pinus chihuahuana, Pinus spp.), some oaks (Quercus crassifolia and Quercus spp.) and cypress (Cupressus arizonica), 1994.07.21, Timdal, E. SON68/31 [27°26.3'N, 107°29.3'W]
Currently accepted name:Toninia tristis ssp. chihuahuana Timdal