Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.

Thallus: foliose-fruticose, medium-sized to large, overall up to 5 cm wide, individual rosettes (5-)10-25 mm wide, polyphyllous marginal lobes: broadly rounded adpressed, becoming irregularly shaped ±ascending; 2-4 mm wide, (125-)200-400 µm thick, heteromerous, centrally with loose hyphal strand lacking photobiont cells and 50-350 µm thick, internally reticulate towards the periphery upper surface: black, with conspicuous ±radial folds, otherwise smooth and often with a silky gloss lower surface: concolorous with the upper surface, dull, attached by umbilicus and tufts of rhizohyphae Apothecia: thallinocarpous, usually abundant, 1-3 per lobe, submarginal to marginal, up to 1(-4) mm wide, ±round to irregularly elongated, sessile, convex, disc: rough, distinctly dotted or fissured; margin: thalline, up to 0.1 mm wide, indistinct; proper exciple: thin, up to 5 µm wide, enclosing partial hymenia, hyaline, IKI- hymenium: hyaline, IKI+ blue turning wine red, separated into partial hymenia by intrusions of wedge-like packets of thalline tissue and projecting sterile hyphae from the subhymenium, (50-)75-110 µm wide, (50-)75-100 µm tall, covered by continuous layer of sterile thalline tissue interrupted only by the pore-like discs of the partial hymenia; subhymenium: hyaline, laterally separated corresponding to partial hymenia, IKI+ blue ascus: 16-32-spored ascospores: hyaline, simple, ellipsoid to broad ellipsoid, small, (5-)7-9(-10) x (2-)3-5 µm Pycnidia: globose to broadly pyriform, 80-120 µm wide conidia: ellipsoid to fusiform, 2-5 x 1-2 µm Spot tests: all negative Secondary products: none detected. Substrate and ecology: on siliceous rock in drainage areas World distribution: North America, southern Europe, NW Africa, Middle East, Socotra Sonoran distribution: common in Arizona, California, Baja California, and Baja California Sur. Notes: Lichinella nigritella is similar. It forms, however, ±round, umbilicate cushions and has deeply branched lobes with small, globose isidia on the surface. The lobes are more elongated and the tips often become dissected into small lobules. Furthermore, the lobes are less conspicuously folded and plicate and ±erect from the beginning. In Lichinella cribellifera isidia are usually lacking, the lobes are more sparingly branched with broadly rounded tips, conspicuously folded and plicate and adpressed at the thallus margin.