Pseudoheppia


Pseudoheppia is a fungal genus in the family Porocyphaceae. It contains a single species, Pseudoheppia schuleri, a saxicolous squamulose lichen.

Taxonomy

Both the genus Pseudoheppia and its sole species were introduced to science in 1903 by the Austrian lichenologist Alexander Zahlbruckner. The species epithet honours the lichenologist Johann Alois Ernst Schuler, who collected the type species. He collected the type near Fiume in Croatia, specifically on dolomitic limestone. The type specimen is now housed in the herbarium of the Natural History Museum in Vienna.
Pseudoheppia was previously classified in the family Heppiaceae, and later treated within Lichinaceae. In 2024, María Prieto, Mats Wedin and Matthias Schultz placed Heppiaceae, Ephebaceae and Pyrenopsidaceae in synonymy under an emended Porocyphaceae, which now includes Pseudoheppia. The family placement is considered provisional pending additional molecular sampling.

Description

Genus Pseudoheppia features a thallus. The thallus lacks rhizines ; instead, the lichen attaches to the surface through medullary hyphae, which are fungal filaments found in the inner layer of the thallus. The structure of the thallus is, meaning it has a uniform texture throughout, without distinct layers. Pseudoheppia does not have a gelatinous texture, a protective outer, or tissue.
The hyphae within the thallus are densely packed, and the lichen contains a type of cyanobacteria called Scytonema as its . These cyanobacterial cells are bluish-green and are arranged in clustered chains, contributing to the overall structure and appearance of the thallus.
The apothecia are embedded within the thallus and remain throughout their development. These apothecia lack a distinct outer layer, and the base layer of the thallus, the, is pale in colour. The lichen produces simple, colourless spores, with eight spores typically found in each spore-producing structure., which are common in some lichens, have not been observed to occur in Pseudoheppia.
Pseudoheppia can be distinguished from the closely related genus Heppia by its lack of pseudoparenchymatous tissue in the thallus, which is a key difference in its structure.