Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: foliose to caespitose-subfruticose, irregular, very loosely adnate, up to 7 cm in diam., ± dichotomously lobate lobes: linear, elongate, up to 2 mm broad, but usually around 1 mm, 10-20 mm long, ± plane, sometimes prostrate but more often ascending, sometimes minutely bullate, ciliate; cilia: marginal, simple, black tipped, up to 7 mm long upper surface: gray to dark gray, usually with black spots from the abundant pycnidia; soredia and isidia absent upper cortex: prosoplectenchymatous medulla: white, lax, usually well developed lower cortex: lacking throughout lower surface: white, without a cortex, uneven, arachnoid, erhizinate Apothecia: ± abundant, very variable in size, short stipitate, up to 5 mm diam., without cilia on the margin; disc: black, plane, often pruinose asci: subclavate to clavate, 8-spored ascospores: brown, l-septate, ellipsoid, Physcia-type, (16-) 18-20.5 (-21.5) x (7.5-) 8-9.5 (-11) µm Pycnidia: ± abundant, inserted in thallus with black openings on the lobes conidia: bacilliform, 3.5-5 x 1µm Spot tests: cortex K+ yellow C-, KC-, P+ yellow; medulla K+ yellow, C-, KC-, P- Secondary metabolites: cortex with atranorin and chloroatranorin; medulla with atranorin and zeorin. Substrate and ecology: growing on tree trunks, shrubs and cacti in open situations World and Sonoran distribution: known from ± coastal parts of Baja California, Baja California Sur and southern California. Notes: The ± flat lobes with marginal cilia and abundant apothecia makes this common, coastal species easy to recognize.