Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: dwarf-fruticose, forming very small cushions, up to 2.5 mm diam., with jet black, terete, delicately branched lobules lobules: cylindrical, elongated, repeatedly branched, with rounded tips, c. 75-200(-300) µm long, 60-90 µm thick anatomy: heteromerous, ecorticate, composed of a central strand of ±parallel hyphae and a rather loose hyphal network; photobiont a single-celled cyanobacterium, cells c. 7-12(-15) 5-8(-9) µm penetrated by single haustoria Apothecia: terminal, 0.4-0.5 mm in diam. disc: dark brown to black, dull; thalline margin ±prominent, 90 µm thick; proper exciple: absent hymenium: reddish brown in the upper portions, deep I+ blue, 60-75 µm tall; interascal elements: septate, sparely ramified in the upper part, c. 1-1.5 µm thick, with slightly thickened apices up to 2-2.5 µm wide; subhymeniun: elongated as a stipe; a sci: clavate, 10-14 x 38-45(-50) µm, with distinct gelatinous cap, 8-spored; wall: IKI- but outermost parts staining deep blue in iodine after pretreatment with K ascospores: hyaline, simple, broad ellipsoid to ellipsoid, 7.5-10 x 4-6 µm, with thin walls Pycnidia: immersed conidia: needle- to arc-like, 25-35(-40) x 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on siliceous rocks World distribution: so far only known from the type locality in Coahuila. Notes: According to apothecial and pycnidial characters the new species certainly belongs to Peccania s.str. It is distinguished from other species of the genus by its delicate cushions composed of thin, elonganted branchings which are repeatedly divided. Peccania fontqueriana P. Moreno & Egea, known from the old world, is rather close, but separated by the more robust thallus and lobes, c. 0.1-0.15 mm diam. Superficially, Peccania minutula resembles other small, dwarf-fruticose members of the Lichinaceae, particularly Lichinella stipatula that is similar in growth but is readily identified by the polysporous asci, the lack of hymenial coloration, and short ellipsoid conidia. Furthermore, Lichinella stipatula differs in the thallinocarpous type of fruiting body, and the fountain-like arrangement of the thallus hyphae. Associated cyanobacterial lichens identified on the type material include Pseudopeltula heppioides Henssen, Lichinella stipatula Nyl. and Phloeopeccania pulvinulina J.Steiner. It has not yet been found in the Sonoran area but may eventually be found there.