Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: crustose effuse to squamulose-pulvinate areoles/squamules: (0.1-)0.3-0.7(-1) mm wide, granulose or ± smooth, plane or convex or forming cushions composed of densely aggregated lobules, lobules not branched or sparsely branched, 0.1-0.15 mm wide, up to 0.35(-0.5) mm long upper surface: black, rarely somewhat grayish pruinose, dull, smooth, granulose to nodulose isidia: absent, but erect lobules may appear isidia-like lower surface: concolorous, attached by a small umbilicus or rhizohyphae Apothecia: semi-immersed to sessile or stipitate when terminal on erect lobules, 0.2-0.3(-0.4) mm wide, disc: dark red, at first punctiform and somewhat depressed, later open and ±pale; margin: lacking or slightly prominent, persisting and thalline c. 75 µm wide; proper exciple: lacking epihymenium: faintly yellowish brown, K- hymenium: hyaline, IKI+ blue, up to 125 µm tall; subhymenium: hyaline, IKI+ blue asci: subclavate or subcylindrical, thin walled, IKI-, 16-32-spored, exceptionally 8-spored ascospores: hyaline, simple, globose to broad ellipsoid, small, 5(-7.5) x 5 µm, hyaline Pycnidia: immersed, globose, up to 0.125 mm wide, simple, wall convoluted with age conidia: small, ellipsoid, c. 3 x c. 1 µm Spot tests: all negative Secondary products: none detected. Substrate and ecology: on limestone, caliche and volcanic rock; in shaded or sheltered microhabitats in rocky slopes, washes etc.; coastal to mountainous, rather common but easily overlooked World distribution: Middle East, Canary Islands, and North America Sonoran distribution: Arizona, southern California, Baja California, Baja California Sur, Guadalupe Island and Isla Margarita, Sinaloa. Notes: Phloeopeccania pulvinulina is easily confused with truly crustose species especially when the characteristic small pulvinate squamules are lacking. It is separated from Psorotichia, Lemmopsis, Porocyphus and Pyrenopsis by its loosely reticulate anatomy with large photobiont cells (12.5-20 µm). Sometimes, a hyaline gelatinous sheath surrounding the entire thallus is formed. Typically, there are polysporous asci but 8-spored asci occur sometimes. Anema prodigulum differs in the shape of its squamules, the number and size of its ascospores, and its ascomal development (pycnoascocarp). For separation from Phloeopeccania anemoides see above.