Recent molecular revisions of the Arthoniales (e.g. Ertz & al. 2009, 2014, 2018, Ertz & Tehler 2011, Frisch & al. 2014, 2015) have shown that morphological characters such as growth form, ascocarp type, exciple, hypothecium, ascospores colour and septation pattern, and chemistry are of limited use in delimiting families and genera, which indicates an unusual level of plasticity in this group. Several genera, among them Schismatomma and Lecanactis, were found to be paraphyletic, and several species are now placed into different genera, such as:
Dendrographa Darb. – A genus of c. 6, also fruticose species, one of which was previously included in Schismatomma.
Diromma Ertz & Tehler - A monotypic genus accomodating a species formerly included in Schismatomma, which is strikingly similar to Ocellomma but has a distant position in the phylogenetic tree of the Roccellaceae (Ertz & al. 2014).
Lecanactis Körb. – A genus of the Roccellaceae with c. 25 species in tropical to temperate areas.
Ocellomma Ertz & Tehler - A monotypic genus of the Roccellaceae accomodating a species formerly included in Schismatomma and strikingly similar to Diromma dirinellum. Molecular data, however, show that it is resolved in a very distinct lineage within the Roccellaceae phylogeny, independent from both Diromma and Schismatomma (Ertz & al. 2014).
Psoronactis Ertz & Tehler – A monotypic genus, which includes a species formerly assigned to Lecanactis (Ertz & al. 2014).
Schismatomma A. Massal. - This genus, first treated by Tehler (1993, 1994), proved to be heterogeneous and includes now c. 10 species.
Snippocia Ertz, Kukwa & Sanderson - A monospecific genus, an unusual member of the Arthoniaceae, with an isolated phylogenetic position, characterized by a persistently sterile, sorediate thallus and by chemical characters (Ertz & al. 2018), originally described as a member of Schismatomma.
Sporodophoron Frisch, Y. Ohmura, Ertz & G. Thor – A genus created to accommodate 4 species with the same characteristics of Inoderma, but forming sporodochia instead of pycnidia. The European species was formerly treated as a member of Schismatomma (Frisch & al. 2014).
The present key includes all species of these genera known to occur in Italy (Nimis 2016), for a total of 10 species.

References

Ertz D., Tehler A. 2011. The phylogeny of Arthoniales (Pezizomycotina) inferred from nucLSU and RPB2 sequences. Fungal Divers., 49, 1: 47-71.
Ertz D., Miadlikowska J., Lutzoni F., Dessein S., Raspe O., Vigneron N., Hofstetter V., Diederich P. 2009. Towards a new classification of the Arthoniales (Ascomycota) based on a three-gene phylogeny focussing on the genus Opegrapha. Mycol. Res., 113: 141-152.
Ertz D., Tehler A., Irestedt M., Frisch A., Thor G., van den Boom P.P.G. 2014. A large-scale phylogenetic revision of Roccellaceae (Arthoniales) reveals eight new genera. Fungal Divers., 70, 1: 31-53.
Ertz D., Sanderson N., Lubeck A., Kukwa M. 2018. Two new species of Arthoniaceae from old-growth European forests, Arthonia thoriana and Inoderma sorediatum, and a new genus for Schismatomma niveum. Lichenologist, 50, 2: 161-172.
Frisch A., Thor G., Ertz D., Grube M. 2014. The Arthonialean challenge: Restructuring Arthoniaceae. Taxon, 63, 4: 727-744.
Frisch A., Ohmura Y., Ertz D., Thor G. 2015. Inoderma and related genera in Arthoniaceae with elevated pruinose pycnidia or sporodochia. Lichenologist, 47, 4: 233-256.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Tehler A. 1993. The genus Schismatomma (Arthoniales, Euascomycetidae). Opera Bot., 118: 1-38.
Tehler A. 1994. Additional notes to the lichen genus Schismatomma (Arthoniales). Mycotaxon, 51: 31-34.

Last modified: January, 6, 2024

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