MOLECULAR SYSTEMATICS OF LECANORA-SUBGENUS PLACODIUM

A first hypothesis for the phylogeny of Lecanora subgen. Placodium is presented by using molecular data. Previous evolutionary ideas and cla ssification concepts for this group with non-molecular data are re-inv estigated using DNA sequence data from the nuclear ITS and 5.8S region s. Using Protoparmelia as an outgroup, the Lecanora subfusca group tog ether with the L. rupicola group appear as a sister group to assemblag es with lobate species. Subgen. Placodium, as currently accepted, is n ot monophyletic. Molecular data suggest that the Lecanora dispersa gro up and the L. polytropa group are widened by lobate species and there is evidence from the ITS data that the monotypic genus Arctopeltis Poe lt is closely related to the L. dispersa group. A congruence between m olecular data and secondary chemistry supports the broader concept of the L. dispersa group suggested by the molecular data. (C) 1998 The Br itish Lichen Society.