Description

 Thallus: peltate, irregularly orbicular, lobate; lobes: 2-8 mm in diam., heteromerous; margins: downcurved or raised, entire or broken; upper surface: yellow to brown-olive, with pale c. 40 µm deep depressions in a reticulate pattern; cortex: 25-50 (-75) µm thick; cells: 5-13 µm in diam.; epinecral layer: up to 45 µm thick; medulla: composed of anticlinally oriented hyphae, 3-8 µm thick, basally with globose, enlarged cells (up to 14.5 µm in diam.); cyanobacteria distributed throughout; lower cortex: not developed or only rudimentary at the margin of young lobes; Apothecia: one to several per lobe; disc: red-brown, urceolate, up to 2 mm diam.; exciple: 25-70 µm thick; hymenium: (115-) 140-175 µm tall, I+ blue or in part reddish; subhymenium: 20-50 µm thick; asci: cylindrical to obovoid, 8-spored; ascospores: simple, ellipsoid to fusiform, (15-) 17-29 (-32) x (5-) 8-10.5 (-12) µm; Pycnidia: immersed; conidia: fusiform, 2.5-3.5 x 1-1.5 µm; Spot tests: all negative; Secondary metabolites: none detected.; Substrate and ecology: usually on soil, sometimes on soil over acidic rocks, occasionally in calcareous areas; World distribution: SW North America, SW Europe, northern Africa and Australasia; Sonoran distribution: Arizona and Baja California Sur.; Notes: The mottled, superficial appearance of this species due to the deep, reticulate depressions in the upper surface is a feature by which the species can be readily recognized.