Parmeliella is a genus of lichen-forming fungi in the family Pannariaceae. It occurs mainly in the tropics and subtropics, with species found in Africa, Asia, Australasia and South America. These lichens form small, leaf-like or crusty patches that are often anchored by blue-black fibres, and they partner with nitrogen-fixing cyanobacteria. The genus was established in 1862 by the Swiss lichenologist Johannes Müller Argoviensis, who distinguished it from related genera by the structure of its fruiting bodies.
Taxonomy
The genus was circumscribed by the Swiss lichenologist Johannes Müller Argoviensis in 1862. In his original description, Müller Argoviensis distinguished Parmeliella from the genus Pannaria primarily by the structure of the fruiting bodies (apothecia). He noted that Parmeliella species have apothecia with a proper margin that lacks photobiont cells (gonidia) from the beginning and becomes somewhat sunken into the thallus as it ages, contrasting with the swollen, photobiont-rich margins typical of Pannaria. The spores were described as hyaline (colourless) and simple in structure. Müller Argoviensis initially included two species in the genus: P. triptophylla and P. turgida, both found in the high forests of the Dôle region near Geneva, particularly on Sorbus aucuparia (rowan trees) and less commonly on beech and fir trunks.
