KEYS TO THE LICHENS OF ITALY - 66) MICROFILAMENTOUS LICHENS (Cystocoleus, Ephebe, Polychidium, Spilonema, Racodium, Thermutis, Zalbrucknerella)
Pier Luigi Nimis
Apparatus of images: Andrea Moro - Software and databases: Stefano Martellos

This is a key to all blackish microfilamentous lichens (with <60 μm thick filaments) which are known to occur in Italy (Nimis 2016), with the addition of some species known from neighbouring countries in the Alps (Nimis & al. 2018), for a total of 11 species.
Species of the following genera are included:
1+2) Cystocoleus Thwaites and Racodium Fr. - Two enigmatic sterile filamentous lichens, characterised by fungal hyphae which surround a filament of the green alga Trentepohlia. Despite their anatomical similarity, molecular data have now shown that the two monotypic genera are not part of a single monophyletic group (Muggia & al. 2008), although they are both still classified in the Racodiaceae.
3) Ephebe Fr. - A genus of the Lichinaceae with 13 species with a thread-like thallus, where the photosynthetic partner is Stigonema, with the highest diversity in cold regions. A key to Scandinavian species in Jørgensen (2007).
4) Polychidium (Ach.) Gray - Wedin & al. (2007) showed that, together with Massalongia and Leptochidium, this monotypic genus forms a well-supported monophyletic group, which is characterised by both molecular and morphological data. The three genera, which have a similar hemiangiocarpic ascoma ontogeny, similarly built apothecia, and similar asci with an amyloid apical cap, are now placed in the family Massalongiaceae.
5) Spilonema Bornet - This small genus of 4 species, the only one of Peltigerales which includes species with the cyanobacterial genus Stigonema, was long been placed in Coccocarpiaceae based on ascomatal development, a fact that has been confirmed by molecular data (Spribille & al. 2014).
6) Thermutis Fr. - A monotypic genus of the Lichinaceae, the most primitive of the family (Jørgensen 2007), distinguished from other fruticose cyanobacterial lichens by having Scytonema as a photobiont. When sterile, it is difficult to distinguish from free-living Scytonema, as it is weakly lichenised.
7) Zahlbrucknerella Herre - A saxicolous genus of the Lichinaceae with c. 10 species, occurring mostly on rocks along the banks of rivers and lakes, and in moist depressions (one species is maritime), mainly represented in the cool- to cold-temperate regions of both Hemispheres, with the greatest diversity in the Americas.

References

Jørgensen P.M. 2007. Arctomiaceae, Coccocarpiaceae, Collemataceae, Heppiaceae, Lichinaceae, Pannariaceae. Nordic Lichen Flora, Vol 3: Cyanolichens.
Muggia L., Hafellner J., Wirtz N., Hawksworth D.L., Grube M. 2008b. The sterile microfilamentous lichenized fungi Cystocoleus ebeneus and Racodium rupestre are relatives of plant pathogens and clinically important dothidealean fungi. Mycol. Res., 112: 50-56.
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.
Spribille T., Tønsberg T., Stabentheiner E., Muggia L. 2014. Reassessing evolutionary relationships in the filamentous cyanolichen genus Spilonema (Peltigerales, Lecanoromycetes) Lichenologist, 46, 3: 373-388.
Wedin M., Jørgensen P.M., Wiklund E. 2007. Massalongiaceae fam. nov., an overlooked monophyletic group among the cyanobacterial lichens (Peltigerales, Lecanoromycetes, Ascomycota). Lichenologist, 39, 1: 61-67.

Last modified: June, 5th, 2021


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