Calvitimela Armeniaca

''Calvitimela'' is a lichen Tephromelataceae ( Lecanorales, Lecanoromycetes). Members of the family Tephromelataceae are crustose lichens with green photobionts and lecideine or lecanorine apothecia. The species in ''Calvitimela'' have lecideine apothecia, are saxicolous and are primarily found in alpine to arctic regions.

Species

''Calvitimela'' currently includes ten species:

*'' Calvitimela aglaea'' (Sommerf.) Hafellner
*'' Calvitimela armeniaca'' (DC.) Hafellner (type species)
*''Calvitimela austrochilensis'' Fryday
*'' Calvitimela cuprea'' Haugan & Timdal
*'' Calvitimela livida'' Haugan & Timdal
*'' Calvitimela melaleuca'' (Sommerf.) R. Sant
*''Calvitimela perlata'' (Haugan & Timdal) R. Sant
*''Calvitimela septentrionalis'' (Hertel & Rambold) McCune
*'' Calvitimela talayana'' (Haugan & Timdal) M.P. Andreev
*'' Calvitimela uniseptata'' G. Thor

Taxonomy

The taxonomic history of ''Calvitimela'' is long and relatively complex. In the early days, the species now belonging to ''Calvitimela'' were placed in the classical genus ''Lecidea'' Ach., e.g. by Fries (1874; as ''Lecidea'' strips ''L. armeniacae''). and Magnusson (1931; as “''Lecidea armeniaca''- und ''elata''-Gruppe”) In the 1980s, several taxonomists revised large groups of lichens in ''Lecanora'' and ''Lecidea''. First, the generic name ''Tephromela'' was resurrected, and the new monotypic family Tephromelataceae described. Then, a group from ''Lecidea'' was moved into the genus ''Tephromela'' M. Choisy. This led to species with both lecanorine and lecideine apothecia being present in the same genus. Finally, the genus ''Calvitimela'' was erected for species with lecideine apothecia previously placed in ''Tephromela''. Tephromelataceae consists of the ''Tephromela'', ''Calvitimela'', ''Mycoblastus'' Norman and ''Violella'' T. Sprib, and together these four genera constitute a well-supported monophyletic group.

Morphology, anatomy, and chemistry

The species of ''Calvitimela'' are crustose lichens. Their thallus are areolate and their apothecia lecideine. The apothecia are convex, black and shiny. Apothecia are rare or entirely absent in some sorediate species e.g. ''C. cuprea'', ''C. livida'' and ''C. talayana''.

Ascii are generally of the ''Lecanora''-type, but ''Bacidia''-type ascii are also observed in ''C. aglaea'' and ''C. perlata''. The spores are usually simple and ellipsoid. There is much chemical variation of secondary metabolites in the species of ''Calvitimela''. Most prominently observed in the ''C. melaleuca'' – complex, with alectorialic, norstictic, roccellic and psoromic acids occurring in different combinations in the species´ several chemotypes.

Ecology and distribution

All species of ''Calvitimela'' grow on rocks. The species in ''Calvitimela'' reside either on boulders of varying size or directly on mountainous walls and are occasionally found on pebbles. A peculiar ecological preference is observed in ''C. cuprea''. This species is more or less morphologically identical to ''C. livida'', but seem to only grow on copper rich rocks, and is associated with old copper mine localities.

Species in ''Calvitimela'' are predominantly distributed in alpine to arctic regions, and they seem to have a circumpolar distribution. On the other hand, due to lack of sampling in certain regions of the world (e.g. Africa, Asia and South America), the true distribution of ''Calvitimela'' is only partly known. ''C. austrochilensis'' is described from Chile and ''C. uniseptata'' from Antarctica, respectively. These species have not yet been included in any molecular phylogenetic studies. Therefore, whether they belong in ''Calvitimela'' or not, is yet to be confirmed by molecular data.

Phylogeny

Molecular phylogenetics has revolutionized the taxonomy of crustose lichens and revealed an extensive amount of cryptic species diversity. In ''Calvitimela'' there are some species that are morphologically identical, but are genetically distinct and have different chemotypes. In the ''C. melaleuca''– complex at least two distinct chemical lineages are observed with no currently known morphological correlation. There have been few studies investigating ''Calvitimela'' from a molecular phylogenetics perspective. Only one phylogeny focusing exclusively on ''Calvitimela'' has been published. They found ''Calvitimela'', ''Tephromela'' and ''Violella'' to constitute a well-supported monophyletic group. The relationship between the main clades remained partly unresolved, however. No study has yet included all species currently circumscribed to ''Calvitimela'', but the genus is so far indicated to be paraphyletic.

References

{{Taxonbar, from=Q10440768

Lecanorales
Lecanorales genera
Lichen genera
Taxa named by Josef Hafellner
Taxa described in 2001