Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Pseudothecia: 150-250 mm diam., immersed in the host thallus, sometimes inducing the formation of convex cecidia ascomatal wall: colorless or slightly green-blue in its lower half, intensively green-blue around the ostiole, basally 10-15(-20) µm thick paraphysoids: scarce, 1.5(-2) µm thick asci: cylindrical, (55-)65-90 x 9-11 µm, 4-spored, exceptionally 8-spored ascospores: hyaline, 1septate, narrowly ellipsoid or fusiform, (19-)20-25(-30) x 4-6(-7) µm, with both cells equal in shape and size, with the septum centered, more rarely slightly heteropolar. Hosts: on the thallus of taxa of the Lecanora muralis group, growing both on siliceous and carbonated substrata; in Sonoran region known on Lecanora garovaglii, L. muralis and L. novomexicana World distribution: holarctic, not frequent, but locally abundant Sonoran distribution: Arizona. Notes: Santesson (1960) and Grube & Hafellner (1990) regard Phacopsis macrospora as a possible synonym of