Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: crustose, thin, granulose to irregularly areolate areoles: irregularly shaped, 0.1.5-0.4 mm wide, diffuse to somewhat aggregated upper surface: blackish, finely granulose, dull; isidia: absent lower surface: attached by rhizohyphae Apothecia: semi-immersed to sessile, small, c. 0.2 mm wide disc: punctiform to somewhat opened, slightly depressed, black and well contrasting with thallus when moist, becoming umbonate, with persisting, smooth thalline margin proper exciple: thin, IKI- hymenium: hyaline, 80-100 µm tall, IKI-, usually with central intrusions of sterile hyphae forming small umbo; epihymenium: bluish green, K- asci: subclavate, subbiseriate, 16-spored ascospores: simple, hyaline, ellipsoid to broad ellipsoid, small, 5-8 x 3-5 µm Pycnidia: immersed, broadly pyriform, hyaline, (0.05-)0.1-0.125 mm wide, simple or wall finally slightly convoluted conidia: broad ellipsoid, (2-)2.5-3.5 x 1.5-2 µm Spot tests: all negative Secondary products: none detected. Substrate and ecology: on sandstone; in exposed habitats along seepage tracks or on steep, shaded rock faces World distribution: previously known from Crimea Peninsula and Ukraine, but recently also reported from the Czech Republic Sonoran distribution: northern Arizona. Note: For separation from Psorotichia numidella var. flageyana see the notes under that species.