Banachtiloissa

Banachtiloissa is a genus of lichenized fungi classified within the family Parmeliaceae. The genus was described in the early 21st century by a team of mycologists, who named it to honor mathematician Stefan Banach and to reflect the structured, lattice-like arrangement observed in its thallus. The type species is Banachtiloissa maritima, described from coastal rocky habitats.

Description and characteristics include foliose lichens with a flattened thallus that ranges from 1 to 4 cm across. The upper surface is gray-green to olive-gray, typically smooth or slightly wrinkled, with margins that are often loosely ciliate. The lower surface is usually darkened near the central axis and may bear rhizines. The photobiont partner is a green alga, commonly from the genus Trebouxia. Apothecia, when present, are disc-shaped, brown, and range from about 0.5 to 1.5 mm in diameter. Asci generally contain eight smooth, ellipsoid ascospores measuring roughly 6–9 by 4–5 μm.

Habitat and distribution extend across temperate to boreal forests, with a preference for shaded, humid microhabitats on siliceous rock or bark. Banachtiloissa has been reported from coastal regions of North America and parts of northern Europe, often at elevations from sea level to about 1200 meters.

Species and taxonomy: at present, the genus includes two described species, Banachtiloissa maritima and Banachtiloissa borealis. They are distinguished by substrate affinity and subtle thallus coloration, though both share the characteristic foliose morphology and Trebouxia photobiont.

Ecology and significance: like many lichens, Banachtiloissa species contribute to nutrient cycling, provide microhabitat structures, and can serve as indicators of air quality. Conservation considerations are limited by available data, but habitat disturbance and pollution remain general concerns for lichens in temperate and boreal ecosystems.