Biology:Gonotichia
Gonotichia is a small genus of cyanolichens (lichens that partner with cyanobacteria) in the family Lichinellaceae. The genus was established in 2024 as part of a major reorganisation of cyanolichen classification based on DNA studies, and contains just two species that form tiny, dark crusts on sun-exposed rocks. These lichens are characterised by their distinctive reproductive structures that develop as swellings within the lichen body rather than as separate disc-like structures on the surface.
Taxonomy
The genus was circumscribed by Matthias Schultz and María Prieto as part of a class-wide phylogenetic revision that reorganised Lichinomycetes into four families (three emended and one new). Within this scheme, Gonotichia forms a distinct clade in Lichinellaceae, which the authors diagnose chiefly by thallinocarpous ascomata and a Lichinella-type ascus. The type species is Gonotichia octosporella, a taxon that was originally described as Gonohymenia octosporella by Georg Lettau in 1942.[1] A second species, G. depauperata (originally described as Gonohymenia myriospora var. depauperata by Miroslav Servít in 1937[2]), was also included in the original treatment.[3]
Description
Species of Gonotichia are minute, rock-dwelling cyanolichens. The thallus (lichen body) is crustose, forming thin, dark, irregular patches ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) on the substrate rather than a leafy or shrubby form. The sexual reproductive structures are [[Glossary of lichen terms#{{biology:{1}}}|thallinocarpous]], i.e. the ascomata develop within swellings of the thallus instead of as open, disc-like apothecia on the surface. Asci conform to the Lichinella-type used to characterise Lichinellaceae; in the type species they bear eight ascospores.[3]
Habitat and distribution
Gonotichia species occur on sun-exposed mineral substrates, especially siliceous rock, in open sites. Their very small, dark crusts are typical of many Lichinellaceae, which are scattered but widespread in suitable dry, well-lit habitats.[3]
Species
The following species are accepted in the 2024 treatment:[3]
- Gonotichia depauperata (Servít) M.Schultz & M.Prieto (2024)
- Gonotichia octosporella (Lettau) M.Schultz & M.Prieto (2024)
References
- ↑ Lettau, G. (1942). "Flechten aus Mitteleuropa. VII" (in de). Feddes Repertorium Specierum Novarum Regni Vegetabilis Beiheft 119 (5): 265–348 [269].
- ↑ Servít, M. (1937). "Seltenere und neue Flechten" (in de). Vestnik Královske Ceské Spolecnosti Nauk 1936: 1–16 [7].
- ↑ 3.0 3.1 3.2 3.3 Prieto, M.; Wedin, M.; Schultz, M. (2024). "Phylogeny, evolution and a re-classification of the Lichinomycetes". Studies in Mycology 109: 595–655. doi:10.3114/sim.2024.109.09. PMID 39717657.
Wikidata ☰ Q136475836 entry
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