ABSTRACT: Cortinarius vernicosus, a new spring species in mature to late successional conifer forests, is described from two disjunct localities of Washington State in western North America. It is a member of subgenus Myxacium, section Myxacium, due to its cylindrical stipe and the presence of clamp connections throughout the sporocarp. The relationship of C. vernicosus to other members of section Myxacium, based on morphological and phylogenetic data, is discussed. Vegetation, geology and soils are compared and contrasted for the two localities. With this addition, there are six species of section Myxacium known from western North America.

KEYWORDS: Agaricales, Basidiomycetes, Cortinariaceae, macrofungi, taxonomy

NOMENCLATURAL NOVELTIES:
Cortinarius vernicosus M. T. Seidl, p. 116