Lithographa
From Wikipedia, the free encyclopedia
| Lithographa | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Baeomycetales |
| Family: | Xylographaceae |
| Genus: | Lithographa Nyl. (1857) |
| Type species | |
| Lithographa petraea (Nyl.) Nyl. (1856) | |
| Species | |
|
L. graphidioides | |
Lithographa is a genus of lichen-forming fungi in the family Xylographaceae.[1] These rock-dwelling lichens form tightly attached crusts that crack into small tile-like patches, typically appearing in shades of grey, brown, or nearly black. The genus includes six species found primarily in cold regions and high mountains, where they grow on hard rock surfaces in harsh environments. They reproduce through distinctive elongated or round fruiting bodies that appear as dark slits or discs embedded in the crusty surface.
The genus was circumscribed in 1857 by the Finnish lichenologist William Nylander, with Lithographa petraea assigned as the type species.[2] This species is now known as Lithographa tesserata.[3] Nylander characterized Lithographa as having a thallus that is evanescent (disappearing) or scarcely visible, with swollen apothecia, a rim-like epithecium, thick convex margins, spore sacs containing numerous spores, and very slender, somewhat branched paraphyses.[2]
Rounded, sometimes gyrose apothecia in the related genus Lambiella set it apart from slit-disc Lithographa. Phylogenetic work places Lithographa in the same clade as bark-dwelling Ptychographa, and both differ from Wadeana, which has a weaker exciple, reddish apothecia and a filamentous green alga (Trentepohlia) as its photobiont.[4]
