Studies in the lichen genus Ochrolechia. 2. Corticolous species of North America

Abstract

Ochrolechia, a widespread genus of crustose lichens, includes 19 species growing on bark in North America. These corticolous species and several non-North American taxa are treated in this paper. Six species and one variety are described as new: O. antillarum, O. gowardii, O. montana, O. juvenalis, O. pseudopallescens, O. subisidiata, and O. trochophora var. pruinirosella. Two species are reduced to synonymy (O. californica Vers, and O. sorediosa Howard); six species are excluded from the North American flora (O. alboflavescens (Wulf.) Zahlbr., O. apiculata Vers., O. pallescens (L.) Massal., O. parella (L.) Massal., O. rhamni-purshianae Senft, O. subviridis (Höeg) Erichsen, and O. turneri (Sm.) Hasselrot). Several synonymies mentioned in the literature are confirmed (O. trochophora (Vainio) Oshio including O. rosella (Tuck.) Vers. and O. orientalis Vainio; O. androgyna (Hoffm.) Arn. including O. pergranulosa (Räs.) Vers, and O. mahluensis Räs.; and O. yasudae Vainio including O. tuckermanii Vers, and O. pennsylvanica Vers.). A key for the determination of all the species treated is presented together with distribution maps and a summary of the chemistry of the group. 5-O-Methylhiascic and 4,5-di-O-methylhiascic acids are reported from Ochrolechia for the first time. Key words: Ochrolechia, Ascomycotina, Pertusariaceae.