Peccania
Peccania is a genus of lichen-forming fungi in the family Phylliscaceae. These lichens are small and form thin, crusty patches or tiny scale-like structures that are tightly attached to rock surfaces. They partner with blue-green bacteria instead of the green algae found in most other lichens, which helps them survive in harsh, drought-prone environments and quickly resume photosynthesis after wetting. Peccania species grow exclusively on rocks, favouring well-lit locations on both limestone and acidic substrates in arid and semi-arid regions, though they can also occupy locally dry spots in otherwise humid landscapes. The genus includes about 22 species distributed worldwide, with their small fruiting bodies appearing as tiny -like structures that are often slightly sunken into the thallus surface.
Taxonomy
Peccania was validly published by the Bavarian lichenologist Ferdinand [Christian Gustav Arnold|Arnold] in 1858, who credited Abramo Bartolommeo Massalongo with the name "in lit." dated 4 December 1856; Arnold's protologue listed P. coralloides and cited limestone localities around Streitberg in the Franconian Jura. The genus name Peccania is treated as a conserved name under the International Code of Nomenclature for algae, [fungi, and plants|International Code of Nomenclature], stabilising its use over Massalongo's earlier generic name Corinophoros. Later alternative or segregate names referring to the same group—Pleoconis, Peccaniopsis and Peccaniomyces —are regarded as synonyms.A class-wide multilocus study published in 2024 reassessed relationships across the Lichinomycetes and proposed a revised, family-level framework; within that scheme Peccania is treated in Phylliscaceae alongside other small, rock-dwelling cyanolichens such as Peltula and Phylliscum. The authors emphasised that earlier, morphology-only arrangements often conflict with DNA-based relationships, and that adoption of the revised classification is ongoing in regional floras and databases, so species assignments within Peccania may be updated as additional material is sequenced and re-examined. Ancestral-state analyses for the class suggest simple, crust-forming lichens with early-developing fruiting bodies and eight-spored asci, providing context for the small, saxicolous genera placed in Phylliscaceae.