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, 100-150 µm in diam. wall: brown, 7-10 µm thick, up to 15 µm near the ostiole, composed of 1-3 layers of cells of 5-10 x 5-7 µm conidiophores: absent conidiogenous cells: hyaline, subglobose, smooth, 4-7 µm in diam. conidia: hyaline, simple, broadly ellipsoid, smooth, 4-5.5(-6) x 2.5-3.5(-4) µm. Hosts: on apothecia of Physcia and Physconia species, not or only slightly damaging the host World distribution: Europe and North America; rarely recorded and obviously rare Sonoran distribution: known from a single locality in southern California. Notes: Black, partly immersed pycnidia belonging to the Physcia thallus are frequently mistaken by lichenologists for a lichenicolous fungus. They are readily distinguished by having subcylindrical conidia (spermatia?) that are only 1 µm wide.