This genus of the Stereocaulaceae, with c. 140 species, was monographed by Lamb (1977, 1978). Traditionally, it included lichens with a crustose primary thallus and a fruticose secondary thallus. This view has changed in recent years, as five crustose species completely lacking a secondary thallus have been transferred to the genus; the phylogenetic analyses by Högnabba (2006) and Högnabba & al. (2014) support the inclusion of the crustose species in Stereocaulon (see also Timdal 2002), while the current infrageneric classification is not supported. Furthermore, species concepts need to be re-examined, as some species do not appear as monophyletic entities in the phylogeny. The genus has been monographed for Poland by Oset (2015).
The present key includes the 13 species known to occur in Italy (Nimis 2016), plus 6 other entities known from the Alps outside the Italian territory (Nimis & al. 2018), for a total of 19 infrageneric taxa.

References

Högnabba F. 2006. Molecular phylogeny of the genus Stereocaulon (Stereocaulaceae, lichenized ascomycetes). Mycol. Res., 10: 1080-1092.
Högnabba F., Pino-Bodas R., Nordin A., Myllys L., Stenroos S. 2014. Phylogenetic position of the crustose Stereocaulon species. Lichenologist, 46, 1: 103-114.
Lamb I.M. 1977. A conspectus of the lichen genus Stereocaulon (Schreb.) Hoffm. J. Hattori Bot. Lab., 43: 191-355.
Lamb I.M. 1978. Keys to the species of the lichen genus Stereocaulon (Schreb.) Hoffm. J. Hattori Bot. Lab., 44: 209-250.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Nimis P.L., Hafellner J., Roux C., Clerc P., Mayrhofer H., Martellos S., Bilovitz P.O. 2018. The Lichens of the Alps. An Annotated Catalogue. Mycokeys, 31: 1-634.
Oset M. 2015. The lichen genus Stereocaulon (Schreb.) Hoffm. in Poland. A taxonomic and ecological study. Monogr. Bot., 104: 1-81.
Timdal E. 2002. Stereocaulon cumulatum comb. nov., another crustose species in the genus. Lichenologist, 34, 1: 7-11.

Last modified: July, 2, 2024

Project Dryades, Department of Life Sciences, University of Trieste - CC BY-SA 4.0