Pier Luigi Nimis
Chrysothrix Mont. presently includes c. 17 species in the family Chrysothricaceae (Nelsen & al. 2009, Ertz & Tehler 2011). The species with a bright yellow thallus (pulvinic acid derivatives) constituted the original core of the genus (Laundon 1981). Recent phylogenetic studies have shown that Chrysothricaceae thus delimited is paraphyletic and further includes taxa lacking pulvinic acid derivatives, which were previously classified in the genus Arthonia (Nelsen & al. 2009; Frisch & al. 2014). Most species occur on acid substrata (bark, lignum or siliceous rocks). The genus, in its present circumscription (including Alysphaeria), seems to be heterogeneous. It was monographed for Australia by Elix & Kantvilas (2007). Information on individual species can be found in Thor (1988), Tønsberg (1992, 1994, 2004), Kalb (2001), Harris & Ladd (2008), Smith & al. (2009), Lendemer & Elix (2010), Wirth & al. (2013).
The present key includes the 4 species known to occur in Italy (Nimis 2016), plus a further species whose presence in the country is possible.


Harris R.C., Ladd D. 2008. The lichen genus Chrysothrix in the Ozark ecoregion, including a preliminary treatment for eastern and central North America. Opuscula Philolich., 5: 29-42.
Lendemer J.C., Elix J.A. 2010. Two new species of Chrysothrix from eastern North America. Opuscula Philolich., 8: 51-58.
Elix J., Kantvilas G. 2007. The genus Chrysothrix in Australia. Lichenologist, 39: 361-369.
Kalb K. 2001. New or otherwise interesting lichens. I. Bibl. Lichenol., 78: 141-167.
Ertz D., Tehler A. 2011. The phylogeny of Arthoniales (Pezizomycotina) inferred from nucLSU and RPB2 sequences. Fungal Diversity, 49: 47-71.
Frisch A., Thor G., Ertz D., Grube M. 2014. The Arthonialean challenge: Restructuring Arthoniaceae. Taxon, 63, 4: 727-744.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Smith C.W., Aptroot A., Coppins B.J., Fletcher A., Gilbert O.L., James P.W., Wolseley P.A. (eds.) 2009. The Lichens of Great Britain and Ireland. British Lichen Society, London. 1046 pp.
Thor G. 1988. Two new species of Chrysothrix from South America. Bryologist, 91, 4: 360-363.
Tønsberg T. 1992. The sorediate and isidiate, corticolous, crustose lichens in Norway. Sommerfeltia, 14: 1-331.
Tønsberg T. 1994. Chrysothrix flavovirens sp. nov. - the sorediate counterpart of C. chrysophthalma. Graphis Scripta, 6: 31-33.
Tønsberg T. 2004. Chrysothrix. In: Nash T.H: III & al. (eds.), Lichen Flora of the Greater Sonoran Desert Region, Vol. 2, pp. 62-63. Tempe, Lichens Unlimited, Arizona State University.

Last modified: September, 7, 2022