Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Pycnidia: immersed or erumpent, black, subglobose, ostiolate, 40-80 µm in diam. wall: brown to dark brown, 7-10 µm thick, thicker around the ostiole, composed of 2-3 layers of cells 5-7 x 3-4 µm conidiophores: absent ogenous cells: hyaline, subglobose to broadly obpyriform, smooth, 2-3 x 1-2 µm conidia: hyaline, simple, narrowly ellipsoid, sometimes curved, smooth, 5-7 x 1.5-2 µm. Hosts: on thallus and soredia of Flavoparmelia caperata (host of the type), and on thallus of Hypotrachyna, Parmelia s. str., Parmotrema and Rimelia World distribution: Europe and the U.S.A. Sonoran distribution: collected twice in southern California on F. caperata; probably overlooked and more common. Notes: Phoma cytospora should not be confused with Lichenoconium species, that often grow on Parmelia s. l. and have brown, subspherical, verruculose conidia.