Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, distinct, composed of scattered relatively large granules to areolate areoles: flat to convex, corticate surface: chalky white, esorediate Apothecia: occurring singly or in groups, sessile or slightly immersed into areoles of thallus, concave or flat when mature or rarely slightly convex, 0.6-1.4 mm in diam. disc: reddish dark brown to black, epruinose, smooth, with or without an epipsamma (soluble in N) margin: white or rarely pale brown, distinctly prominent, or even with disc, thick and slightly crenulate when mature, epruinose or pruinose and then even scabrous, without a parathecial ring amphithecium: present, with abundant algae marginally or not, c.180 µm thick, corticate; cortex: +distinctly delimited, ±120 µm thick, ±obscured by granules (pol+, insoluble in K, soluble in N) parathecium: pale yellow, distinct, 10-20 µm wide epihymenium: yellow, brown or reddish brown (turning olive in K), lacking granules or with sparse granules (insoluble in K, insoluble in N) hymenium: hyaline, 70-90 µm tall; paraphyses: thick (c. 2 µm below) and adglutinated, slightly branched, with end cell distinctly enlargered to a width of 3.5-4.5 µm and pigmented, coherent in K; subhymenium: hyaline, distinct; hypothecium: hyaline or almost so, composed of adglutinated hyphae to almost cellular, ±70 µm thick asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 13.3-16.3 x 5.9-7.4 µm Pycnidia: not seen Spot tests: all negative Secondary metabolites: not investigated. Substrate and ecology: on exposed sandstone rocks and on soil World distribution: western North America Sonoran distribution: northern Arizona and southern California. Notes: This forgotten taxon is the only member of the L. dispersa group in the region with a very distinct, white, superficial thallus. Although it was very difficult to relate the well-developed Sonoran material with the badly parasitised type specimen, they seem to represent the same taxon.