Psoroma nivale (Pannariaceae, lichenized Ascomycota) a New species with dark, elongate squamules and bacilliform ascospores from arctic Québec, Canada.

Abstract

The new species Psoroma nivale is described from an area of late snow-lie in the Keglo Bay area on the eastern side of Ungava Bay, northern Québec, Canada. It is superficially similar to P. hypnorum but has a dark, brownish black thallus colour without reddish hues, much-branched, proliferating squamules, thick paraphyses, distinct but inconspicuous IKI+ ascus tube structures, and characteristic elongate, bacilliform, often asymmetrical ascospores. The new species is compared with possible related taxa and its systematic position discussed. A key to the species of pannarioid lichens reported from arctic areas of North America is also provided.