This is a key to all species of Pertusariaceae and Ochrolechiaceae known to occur in Italy (Lepra, Ochrolechia, Pertusaria, Varicellaria), plus a few species known from neighbouring countries and whose presence in Italy is possible, for a total of 77 infrageneric taxa (see Nimis 2016).
Schmitt & al. (2006) have re-delimited the family Pertusariaceae s.str. to include only Pertusaria s.str. and Loxosporopsis, that have an unsupported sister-group relationship with Coccotremataceae, while Varicellaria and the Variolaria-group are sister to Ochrolechia in the Ochrolechiaceae.
The four genera included in the key are briefly discussed in the following:
Lepra - Recently, several species of the Variolaria-group were segregated in the genus Variolaria Pers. (Lendemer & al. 2013b), but, due to the fact that this is a later homonym of Variolaria Ball., they were placed by Kondratyuk & al. (2015b) in the new genus Marfloraea, which is illegitimate because several earlier generic names exist for this group, the earliest one being Lepra Scop. (see Hafellner & Türk 2016; Jørgensen & Nimis 2019).
Ochrolechia - This genus of the Ochrolechiaceae, comprising c. 60 crustose species with a usually conspicuous thallus and large apothecia, is distinguished by a hamathecium of branched and anastomosing paraphysoids, strongly amyloid hymenium and asci, and large, simple, thin-walled ascospores. The European species have been monographed by Kukwa (2011). Prelimary results from the phylogenetic analysis by Kukwa & al. (2016) indicate the presence of several previously unknown lineages which are mostly supported by morphological, chemical or biogeographic data, suggesting that a purely morphology-based taxonomy is misleading in Ochrolechia, and that revisions of the genus will include several new taxa as well as reinstatements of synonyms.
Pertusaria - In the traditional circumscription, Pertusaria was a very large genus with possibly over 1000 species. However, the genus has been shown to be polyphyletic, with species belonging even to different families within the order Pertusariales (see e.g. Schmitt & al. 2012). Schmitt & Lumbsch (2004) identified two main clades that are not closely related to Pertusaria s.str. and are now included into the Ochrolechiaceae: the Variolaria- and Varicellaria-groups. The former is now segregated into Lepra, the latter, including the lecanoric acid-containing species, forms a well-supported, monophyletic clade, which is only distantly related to Pertusaria s.str., and is now included in the genus Varicellaria.
Varicellaria - This genus includes species containing lecanoric acid as a major constituent, disciform apothecia, strongly amyloid asci, non-amyloid hymenial gel, 1-2-spored asci, and 1- or 2-celled ascospores with thick, 1-layered walls (see Schmitt & al. 2012).
Other important works dealing with the lichens of this groups in Europe are: Erichsen (1936), Hanko (1983), Clauzade & Roux (1985), Tønsberg (1992), Boqueras (1997, 1999), Boqueras & Llimona (2003) and Wirth & al.(2013). A key to European species of Pertusaria s.lat. was published online by Sipman at https://archive.bgbm.org/sipman/keys/perteuro.htm

References

Boqueras M. 1997. Els gèneres Ochrolechia i Pertusaria a l'herbari Werner. Acta Bot. Barc. 44: 17-28.
Boqueras M. 1999. El género Ochrolechia A. Massal. (Pertusariaceae, líquenes) en España y Portugal. Cryprogamie, Mycol. 20: 303-328.
Boqueras M. & Llimona, X. 2003. The genus Pertusaria (lichenised ascomycotina) on the Iberian Peninsula and Balearic Islands. I. Subgenus Pertusaria. Mycotaxon 88: 471-492.
Clauzade G. & C. Roux 1985. Likenoj de okcidenta Europo, Ilustrita Determinlibro. Bull. Soc. Bot. Centre-Ouest NS, Num. Spéc. 7, 893 pp.
Erichsen C.F.E. 1936. Pertusariaceae, pp. 319-701 in A. Zahlbruckner (Ed.), Rabenhorst's Kryptogamenflora IX, V. I.
Hafellner J., Türk R. 2016. Die lichenisierten Pilze Österreichs - eine neue Checkliste der bisher nachgewiesenen Taxa mit Angaben zu Verbreitung und Substratökologie. - Stapfia, 104, 1: 1-216.
Jørgensen P.M., Nimis P.L. 2019. On the typification of the lichen genus Lepra Scop. Taxon, 68, 1: 132-136.
Kukwa M. 2011. The lichen genus Ochrolechia in Europe. Fundacja Rozwoju Uniwersytetu Gdanskiego, Gdansk, 309 pp.
Kukwa M., Ertz D., Schmitt I. 2016. Evolution of the genus Ochrolechia based on a seven-marker phylogeny and a worldwide sampling. IAL 8, Book of Abstracts, Helsinki: 57.
Lendemer, J. C., Harris, R. C. & Tripp, E. A. 2013. The lichens and allied fungi of Great Smoky Mountains National Park: An annotated checklist with comprehensive keys. Mem. New York Bot. Gard., 104: 1-156.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Schmitt I., Lumbsch H.T. 2004. Molecular phylogeny of the Pertusariaceae supports secondary chemistry as an important systematic character set in lichen-forming Ascomycetes. Mol. Phylogenet. Evol., 33: 43-55.
Schmitt I., Yamamoto Y., Lumbsch H.T. 2006. Phylogeny of Pertusariales (Ascomycotina): Resurrection of Ochrolechiaceae and new circumscription of Megasporaceae. J. Hattori Bot. Lab.: 753-764.
Schmitt I., Otte J., Parnmen S., Sadowska-Deś A.D., Lücking R., Lumbsch H.T. 2012. A new circumscription of the genus Varicellaria (Pertusariales, Ascomycota). MycoKeys, 4: 23-36.
Tønsberg T. 1992. The sorediate and isidiate, corticolous, crustose lichens in Norway. Sommerfeltia 14: 1-331.
Wirth V., Hauck M., Schultz M. 2013. Die Flechten Deutschlands. Stuttgart, Ulmer. 2 voll., 1244 pp.

Last modified: August, 25, 2023

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