KEYS TO THE LICHENS OF ITALY - 51) ENDOCARPON, NESOTHELE and STAUROTHELE
The genera Endocarpon and Staurothele are characterized by the presence in the perithecia of hymenial stichococcoid algae which are dispersed together with the ascospores. Endocarpon is a genus with c. 70 species occurring in arid to cool-temperate regions, rarely in the tropics; most species have a squamulose thallus and inhabit mineral soils in arid and semi-arid regions, a few grow on rocks or bryophytes, rarely on bark. A molecular analysis of catapyrenioid genera by Prieto & al. (2012) showed that Endocarpon forms a group including Anthracocarpon, Involucropyrenium, Neocatapyrenium, and a subset of Verrucaria-species, characterised by the presence of Endocarpon-type pycnidia, so that several nomenclatural changes are probable in the next future. Staurothele, in the traditional circumscription, comprised c. 72 species, all characterised by a crustose thallus, but a squamulose-subfruticose species has been recently added to the genus by Heiđmarsson & al. (2017). Gueidan & al. (2007) revealed Staurothele to be polyphyletic, a fact confirmed by Savić & al. (2008), who have shown that morphological features traditionally used for characterising the genera Polyblastia, Thelidium, Staurothele and Verrucaria, such as spore septation and colour, occurrence of hymenial photobionts, involucrellum structure, and substrate preference, are not always reliable for characterising natural groups; in particular, hymenial algae seem to have evolved independently in at least three distinct lineages of the Verrucariaceae. Currently, the genus includes c. 40 species. Good descriptions and a key to all British species are in Orange (2013); a comprehensive key to most Italian species is in Clauzade & Roux (1985). Both Endocarpon and Staurothele are insufficiently studied, also in Europe, and the delimitation of several species is problematic.
The present key includes all species known to occur in Italy (Nimis 2016) plus some species which are known from adjacent countries, especially in the Alps (see Nimis & al. 2018), and which should be looked for in Italy, for a total of 36 infrageneric taxa.
Clauzade G., Roux C. 1985. Likenoj de Okcidenta Europo. Ilustrita determinlibro. Bull. Soc. Bot. Centre-Ouest, N. Ser., N. Spec. 7. Royan, 893 pp.
Gueidan C., Roux C., Lutzoni F. 2007. Using a multigene phylogenetic analysis to assess generic delineation and character evolution in Verrucariaceae (Verrucariales, Ascomycota). Mycol. Res., 111: 1145-1168.
Heiđmarsson S., Gueidan C., Miadlikowska J. Lutzoni F. 2017. Multi-locus phylogeny supports the placement of Endocarpon pulvinatum within Staurothele s. str. (lichenised ascomycetes, Eurotiomycetes, Verrucariaceae). Phytotaxa, 306, 1: 37-48.
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.
Orange A. 2013. British and Other Pyrenocarpous Lichens. Vers. II. August 2013. https://museum.wales/.../Orange-A-2013-British-and-other-pyrenocarpous-lichens.pdf
Prieto M., Martinez I., Aragón G., Gueidan C., Lutzoni F. 2012. Molecular phylogeny of Heteroplacidium, Placidium, and related catapyrenioid genera (Verrucariaceae, lichen-forming Ascomycota). Am. J. Bot., 99, 1: 23-35.
Savić S., Tibell L., Gueidan C., Lutzoni F. 2008. Molecular phylogeny and systematics of Polyblastia (Verrucariaceae, Eurotiomycetes) and allied genera. Mycol. Res., 112: 1307-1318.