This key includes all species of Fuscideaceae known to occur in Italy (Nimis 2016), plus a few species which are present in neighbouring countries (see e.g. Nimis & al. 2018) and whose presence in Italy cannot be excluded, for a total of 15 infrageneric taxa.
The following genera are included:
1) Fuscidea V. Wirth & Vězda - A genus with c. 35, corticolous or saxicolous species, mainly occuring in the temperate parts of the Northern Hemisphere, especially in areas with a moist, cool, maritime climate. The genus is mainly defined by the morphology of the apothecia (essentially either sessile and lecideine or immersed and more or less aspicilioid), the size and shape of ascospores, the type of asci, and by thallus chemistry. In its current circumscription, it is not monophyletic, as Maronea is nested within Fuscidea (see Bylin & al. 2007, Zahradníková 2017) . In Europe, the genus was studied by e.g. Magnusson (1925), Oberhollenzer & Wirth (1964,1985, 1990), Wirth & Vězda (1972), Zahradníková & al. (2017); the epiphytic sorediate species were studied by Tønsberg (1992). American species were monographed by Fryday (2008). For the differences between F. lighfootii and F. pusilla see Zahradníková & al. (2018).
3) Maronea A. Massal. - A genus of c. 13 species, mainly found in tropical to warm-temperate regions, with one corticolous species widespread in Australasia. Early authors included the genus in the Acarosporaceae on account of the large number of spores in the asci, but the genus is very closely related to Fuscidea; despite striking differences in ascocarp anatomy and spore number per ascus, the two genera share a unique ascus type and a distinctive type of epihymenial pigmentation (see Bylin & al. 2007).
3) Ropalospora A.Massal. - As presently circumscribed, Ropalospora includes 7 saxicolous or corticolous species and is found mainly in temperate parts of the Northern Hemisphere. The genus differs from Fuscidea in the multiseptate ascospores, as well as in more subtle features of ascus and exciple anatomy, and is not closely related to Fuscidea (see Bylin & al. 2007).

References

Bylin A., Arnerup J., Hogberg N., Thor G. 2007. A phylogenetic study of Fuscideaceae using mtSSU rDNA. Bibl. Lichenol., 96: 49-60.
Fryday A.M. 2008. The genus Fuscidea (Fuscideaceae, lichenized Ascomycota) in North America. Lichenologist, 40: 295-328.
Magnusson A.H. 1925. Studies in the Rivulosa-group of the genus Lecidea. Göteborgs Kung. Vetensk.Vitterhets–Samh. Handl., 22: 1-50.
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.
Oberhollenzer H., Wirth V. 1984. Beitrage zur Revision der Flechtengattung Fuscidea. Beih. Nova Hedwigia, 79: 562-566.
Oberhollenzer H, Wirth V. 1985. Beiträge zur Revision der Flechtengattung Fuscidea. II: Fuscidea gothoburgensis (H. Magnusson) V. Wirth & Vezda s.l. Stuttg. Beitr. Naturk., A 376: 1-11.
Oberhollenzer H., Wirth V. 1990. Contributions to a revision of the lichen genus Fuscidea. --III: Fuscidea recensa (Stirton) Hertel, V. Wirth & Vezda. Bibl. Lichenol., 38: 367-375.
Tønsberg T. 1992. The sorediate and isidiate, corticolous, crustose lichens in Norway. Sommerfeltia, 14: 1-331.
Wirth V., Vězda A. 1972. Zur Systematik der Lecidea cyathoides-Gruppe. Beitr. naturk. Forsch. Südwestdeutschl., 31: 91-92.
Zahradníková M. 2017. Taxonomy and phylogeny of the family Fuscideaceae (Umbilicariales, Ascomycota) with special emphasis on Fuscidea. Thesis, AIT Bjerch AS, University of Bergen. 196 pp.
Zahradníková M. Tønsberg T., Andersen H.L. 2017. The taxonomy of the lichen Fuscidea cyathoides (Fuscideaceae, Umbilicariomycetidae, Ascomycota) in Europe. Lichenologist, 49, 6: 547-560.
Zahradníková M., Andersen H.L., Tønsberg T. 2018, Fuscidea lightfootii and F. pusilla (Fuscideaceae, Umbilicariomycetidae, Ascomycota), two similar but genetically distinct species. Lichenologist, 50, 4: 425-438.

Last modified: October, 24, 2021