Further evidence for the polyphyly of Lepraria (Lecanorales: Stereocaulaceae)

Abstract

It has been suggested that the usnic acid-containing species of Lepraria do not belong to Lepraria s. str. In addition, the two usnic acid-containing Lepraria species, Lepraria usnica Sipman and Lepraria coriensis (Hue) Sipman, were suspected to be conspecific by some authors. We incorporate molecular sequence data from two independent loci to test several hypotheses regarding the conspecificity and phylogenetic position of these two taxa. The two species do not form a monophyletic clade, thereby rejecting conspecificity, but both fall outside Lepraria s. str. The placement of L. usnica in Pilocarpaceae is well supported, while the familial placement of L. coriensis could not be determined; the species clusters with taxa outside Lecanorales s. str. This study further illustrates the polyphyly of the leprose growth form and also suggests that certain leprarioid lichens may represent sterile forms of otherwise well-known genera, such as Sporopodium in the Pilocarpaceae.