Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Life habit: lichenicolous, commensalistic, immersed in the thallus, not gall-inducing Ascomata: perithecioid, immersed, obpyriform, covered by a thallus layer with only the ostiolar region visible; ascomatal wall: colorless, rarely brownish in the ostiolar region, composed of several layers of tangentially arranged flattened cells hamathecium: indistinct or absent, but periphyses observed in one species; centrum: K/I- asci: unitunicate, thin-walled, clavate, wall apically lacking any visible specialized structures, 4-8-spored, K/I- ascospores: unicellular, hyaline, elongate ellipsoid to limoniform, smooth, without perispore Conidiomata: unknown Geography: Europe, Macaronesia and North America, possibly subcosmopolitan, but all species rarely collected Substrate: species of Leptogium. Notes: This genus resembles Myxophora, of which the only known Sonoran species, M. leptogiophila (G. Winter) Nik. Hoffmann & Hafellner, also grows on Leptogium. Myxophora is easily separated from Obryzum by the presence of numerous paraphysoids and periphyses, and also with an often more pigmented ascomatal wall. The genus has only recently been recognized in the Sonoran area, and therefore it was not included in the key to the lichenicolous genera in volume 2. In Key 5 (lichenicolous perithecioid ascomycetes) the genus would key out near Paranectria and Nectriopsis, from which it is distinguished by immersed perithecia.