Peltigera islandica, a new cyanolichen species in sectionPeltigera(‘P. caninagroup’)

Abstract

AbstractA new cyanolichen,Peltigera islandicasp. nov. in the sectionPeltigera(‘P. caninagroup’) is described from Iceland. This species is similar in general appearance toP. rufescensandP. membranacea, but may be recognized by its downturned lobe tips and narrow lobes, respectively. Most thalli are bright emerald green in colour when moist, although a dark khaki green colourmorph is also documented. Monophyly ofP. islandicas. lat. (i.e. includingP. sp. AsensuO’Brienet al., from Canada) is significantly supported based on ITS sequences and corroborated by molecular synapomorphy (absence of the ITS1 hypervariable region). Analysis of therbcLX locus indicates the cyanobiont ofP. islandica(Nostocsp.) comprises strains belonging to a pool of Icelandic genotypes, some of which are present in otherPeltigeraspecies, includingP.“neorufescens”, another taxon new to Iceland collected during this study. Association with photobionts that are shared by other local species suggestsP. islandicamay be well established in Iceland, but a review of herbarium collections as well as broader field surveys are needed to better characterize its geographical distribution.