Heppia

Heppia is a genus of olive, brownish, grey, or blackish squamulose, crustose, or peltate like lichens. Heppia was once the type genus of the family Heppiaceae, but that family was folded into synonymy with Lichinaceae.

In a multilocus phylogeny and re-classification of the class Lichinomycetes published in 2024, María Prieto, Mats Wedin and Matthias Schultz placed Heppia in the family Porocyphaceae as part of an emended, broader circumscription of that family; earlier treatments that folded Heppiaceae into Lichinaceae are therefore superseded by the new arrangement. Species of Heppia are cyanolichens (usually with filamentous cyanobacteria) that favour open, well-lit habitats on soil or rock, including biological soil crusts in dry regions; they characteristically produce small or peltate to crustose thalli and develop predominantly pycnoascocarpous sexual structures, consistent with the family diagnosis.