Generic concepts in the former Thelotremataceae, now included in the Graphidaceae, have changed considerably within the last decade (Frisch & al. 2006, Rivas Plata & al. 2010, 2012, 2013). The genus Thelotrema Ach., in its modern circumscription, is characterised by immersed-erumpent to sessile, non-carbonised, ecolumellate, perithecioid to apothecioid ascomata with a double margin caused by a free proper exciple, and lateral periphysoids. It comprises c. 110 species, most of which are tropical to subtropical in distribution, occurring predominantly on bark. Species of the Th. lepadinum complex were treated by Salisbury (1972); European species were treated Purvis & al. (1995); a world-wide key to thelotremoid species was published by Rivas Plata & al. (2010).
This small key includes the two species known to occur in Italy (Nimis 2016).

References

Frisch A., Kalb K., Grube M. 2006. Contribution toward a new systematics of the lichen family Thelotremataceae III. Molecular phylogeny of the Thelotremataceae. Bibl. Lichenol., 92: 517-539.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Purvis O.W., Jørgensen P.M., James P.W. 1995. The lichen genus Thelotrema Ach. in Europe. Bibl. Lichenol., 58: 335-360.
Rivas Plata E., Lücking R., Sipman H.J., Mangold A., Kalb K., Lumbsch H.T. 2010. A world-wide key to the thelotremoid Graphidaceae, excluding the Ocellularia-Myriotrema-Stegobolus clade. Lichenologist, 42: 139-185.
Rivas Plata E., Lumbsch H.T., Lücking R. 2012. A new classification for the lichen family Graphidaceae s.lat. (Ascomycota: Lecanoromycetes: Ostropales). Fungal Divers., 52: 107-121.
Rivas Plata E., Parnmen S., Staiger B., Mangold A., Frisch A., Weerakoon G., Hernandez J.E., Caceres M.E.S., Kalb K., Sipman H.J.M., Common R.S., Nelsen M.P., Lücking R., Lumbsch H.T. 2013. A molecular phylogeny of Graphidaceae (Ascomycota, Lecanoromycetes, Ostropales) including 428 species. MycoKeys, 6: 55-94.
Salisbury G. 1972. Thelotrema Ach. Sect. Thelotrema I. The T. lepadinum group. Lichenologist, 5: 262-274.

Last modified: September, 18, 2022

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