In the past, the genus Catillaria included almost all crustose lichens with a trebouxioid photobiont, lecideine or biatorine apothecia, and 1-septate ascospores. Many species were subsequently segregated into other, often unrelated genera, such as Catinaria, Cliostomum, Fellhanera, Gilbertaria, Kiliasia, and Megalaria.
The present key includes all species of the genera listed below which were reported from Italy (see Nimis 2016), plus a few species known from neighbouring countries (see e.g. Nimis & al. 2018) which should be looked for in Italy; it also includes a few species of other genera (Fellhanera, Bryobilimbia, Mycobilimbia, Toninia) with 1-septate ascospores, for a total of 36 infrageneric taxa.
Catillaria A. Massal. - Catillaria in the strict sense is now defined as having a crustose thallus with a chlorococcoid photobiont (but some species are non-lichenised), lecideine apothecia with a persistent margin, asci with a well-developed amyloid tholus that lacks any discernible internal structures (Catillaria-type), paraphyses with capitate, pigmented apices, and hyaline, non-halonate, 1-septate ascospores. The saxicolous species of Europe were monographed by Kilias (1981). Several species treated as members of Catillaria s.lat. have been transferred to other genera, and some species still treated under Catillaria do not belong to this genus.
Catinaria Vain. - A genus with 2, mainly epiphytic or lignicolous species with 1-septate spores, lecideine apothecia, and Catillaria-type asci, differing from Megalaria and Phyllopsora in the halonate ascospores and the lack of differentiation of the apical tholus in the ascus. According to Kistenich & al. (2018) the genus does not belong to the Ramalinaceae.
Cliostomum Fr. - This genus is characterised by a crustose, esorediate or sorediate thallus, biatorine or zeorine apothecia that possess crystals and lack pigment or contain a mixture of a green and a reddish brown pigment in the epithecium and proper exciple, wide cell lumina in the proper exciple, moderately branched paraphyses, a Biatora-type ascus, mainly 1- or 3-septate, colourless spores, uni- or multilocular pycnidia, branched conidiophores producing short conidia, and by chemical characters. The genus presently includes c. 20 species, but several more species are expected, since Bacidia s.lat. and Catillaria s.lat. are still incompletely known, and since several species may occur as sterile, sorediate crusts (see Ekman 1997). The genus seems to be the sister group of Ramalina in the Ramalinaceae (Ekman 2001).
Gilbertaria M. Svensson & Fryday - A genus of 4 species, belonging to the Sphaerophoraceae. The two species occurring in Italy were treated as members of Catillaria and Toninia. For further details see Svensson & Fryday (2022).
Kiliasia Hafellner - This genus of the Ramalinaceae, which was included in Toninia by Timdal (1992), includes species from his groups 1, 3, and 7. Morphologically, it is characterized by a more or less crustose thallus, although both non-lichenized and squamulose species occur. The ascospores vary from ellipsoid, 1-septate to shortly bacilliform, 3-septate (Kistenich & al. 2018).
Megalaria Hafellner - This genus of the Ramalinaceae (see Miadlikowska & al. 2014, Kistenich & al. 2018) was separated from Catinaria to include the single species M. grossa, but has subsequently been enlarged by the addition of numerous other morphologically similar taxa, and currently consists of c. 30 species from tropical, temperate and subpolar regions. The genus was originally characterised by asci with an axial body (barrel-shaped in the case of M. grossa but conical in other species), and by spores lacking a distinct perispore, until Ekman & Tønsberg (1996) included further characters, such as the texture of the excipulum and the reactions to K and N of the insoluble apothecial pigments. See also Fryday & Lendemer (2010).

References

Ekman S. 1997. The genus Cliostomum revisited. Symb. Bot. Upsal., 32, 1: 17-28.
Ekman S. 2001. Molecular phylogeny of the Bacidiaceae (Lecanorales, lichenized Ascomycota). Mycol. Res., 105, 7: 783-797.
Ekman S., Tønsberg T. 1996. A new species of Megalaria from the North American west coast, and notes on the generic circumscription. Bryologist, 99: 34-40.
Fryday A.M., Lendemer J.C. 2010. Reassessment of the genus Catillochroma (lichenized Ascomycota, Ramalinaceae). Lichenologist, 42, 5: 587-600.
Kilias R. 1981. Revision gesteinsbewohnender Sippen der Flechtengattung Catillaria Massal. in Europa. Herzogia, 5: 209-448.
Kistenich S., Timdal E., Bendiksby M., Ekman S. 2018. Molecular systematics and character evolution in the lichen family Ramalinaceae (Ascomycota: Lecanorales). Taxon, 67, 5: 871-904.
Miadlikowska J., Kauff F., Högnabba F., Oliver J.C., Molnár K, Fraker E., Gaya E., Hafellner J., Hofstetter V., Gueidan C., Otálora M.A.G., Hodkinson B., Kukwa M., Lücking R., Björk C., Sipman H.J.M., Burgaz A.R., Thell A., Passo A., Myllys L., Goward T., Fern 2014. A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families. Mol. Phylogenet. Evol., 79: 132-168.
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.
Svensson M., Fryday A.M. 2022. Gilbertaria, a first crustose genus in the Sphaerophoraceae (Lecanoromycetes, Ascomycota) for Catillaria contristans, Toninia squalescens and related species. Mycological Progress, 21-90.
Timdal E. 1992. A monograph of the genus Toninia (Lecideaceae, Ascomycetes). Opera Bot., 110: 1-137.

Last modified: August, 22, 2023

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