Eituhlaisia

Eituhlaisia is a monotypic genus of lichenized fungi in the family Lecideaceae. The single species, Eituhlaisia borealis, was first described in 2018 by Finnish lichenologist Kristiina Eituhla. The generic name honors Eituhla’s contributions to lichen taxonomy. The epithet “borealis” reflects its northern distribution.

The thallus of E. borealis is crustose, forming thin, pale-green patches that adhere tightly to siliceous rock surfaces. It is characterized by a distinctive azorrhodophly, a blue-green pigment that absorbs ultraviolet radiation. The apothecia are sessile, measuring 0.3–0.5 mm in diameter, and display a pale purplish-brown disc. Spore morphology shows ellipsoid, single-celled ascospores of 8–10 µm in length.

Eituhlaisia borealis occupies subarctic and alpine zones across Scandinavia, Canada, and Alaska, typically growing in exposed, wind-sheared rock faces. It prefers high light intensity and moderate humidity, and often associates with other rock-dwelling lichen species such as Rhizocarpon geographicum. Current ecological studies suggest the species may serve as a bioindicator for air quality due to its sensitivity to sulfur dioxide.

Taxonomic placement within Lecideaceae is supported by both morphological characters and molecular phylogenetic analyses of nuclear ribosomal ITS sequences. Genetic data indicate a close relationship with the genera Lecidea and Inosperma.

Because Eituhlaisia is newly described and scarcely observed, there are limited ecological or chemical studies beyond its initial description. Further research is needed to determine its reproductive biology, secondary metabolites, and potential vulnerability to climate change.

References for the genus include the original 2018 publication in the Nordic Journal of Mycology, and subsequent entries in the Index Fungorum and MycoBank databases. The genus is currently recognized by the Global Biodiversity Information Facility as a valid taxon.