Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Conidiomata: initially immersed in the host thallus and pycnidia-like with a large apical opening, rapidly erumpent wall: hyaline to brown, irregular in thickness, with cells 2.5-5 µm in diam. iophores: if present, composed of 1-3 cells, occasionally branched, pale brown, subcylindrical, up to 13 µm long, 2-3 µm wide conidiogenous cells: hyaline to pale brown, subcylindrical, with several annellations, 3.5-6.2 x 1.5-2.5 µm conidia: pale brown to brown, 1-septate, smooth, dry, ellipsoid or sometimes obpyriform, with a truncate base, 6.2-7.5 x 2.5-3.7 µm. Hosts: on thallus, more rarely apothecia of Pertusaria species, not visibly damaging the host World distribution: Europe, Azores, New Caledonia, and North America; probably cosmopolitan Sonoran distribution: southern California to Baja California Sur, probably common, but overlooked as only recently described. Notes: Minutoexcipula mariana should not be confused with two Lichenodiplis species confined to Pertusaria, viz. L. pertusariicola (Nyl.) Diederich, distinguished by aseptate conidia, and L. hawksworthii Berger & Diederich, with much larger conidia, 8.5-13 x 4.5-5.5 µm, nor with Minutoexcipula tuckerae.