Adaptive divergence in the neglected alpine moss Lewinskya killiasii (Orthotrichaceae), an example of vicariance on different rock types in bryophytes

Abstract

Abstract We provide an example of ecological vicariance among two epilithic, high mountain taxa of mosses. Phylogenetic analyses using plastid (rps4-trnS, atpB-rbcL, trnL-trnF) and nuclear (EST-115, EST-317, ITS region) markers and morphological data revealed the distinctiveness of the neglected Orthotrichum killiasii, here resurrected from the synonymy of Lewinskya speciosa and newly combined in Lewinskya. Furthermore, our data indicate a speciation process within O. killiasii related to the rock type inhabited (silicate vs. carbonate). We translate this into the recognition of two subspecies, corresponding to O. killiasii s.s. and the recently described O. simonyi. The incongruence between nuclear and plastid markers in some accessions and the partial but rare incongruence between ITS ribotypes and the morphological manifestation in phenotypes indicate incomplete lineage sorting with respect to rather recent segregation and possible gene flow between the two entities.