Fig. 1.

Phylogenetic hypothesis of the ITS locus of Trebouxia species: the 50 % majority rule consensus tree of the Bayesian analysis is presented; branch support (Bayesian PP >95 %/ML bootstrap values >70 %) is reported above or beside branches; branches and DNA extraction numbers of our new Trebouxia sequences (Supplementary Data, Table S1) are highlighted in bold. Incongruences (*1–8) of photobiont identities recovered between culture isolates and their original lichen thalli are colour-coded. DNA extraction numbers from cultures are in italics. Sequences retrieved from GenBank are reported in Supplementary Data Table S2. The growth substrate of lichens from which Trebouxia sequences were obtained is colour-coded beside the clades: green, bark, grey, rock (calcareous and siliceous), brown, soil.