Taxonomic and phylogenetic evidence reveal two new Volvariella species (Agaricales, Volvariellaceae) from Denmark

Two new species of Volvariella from Denmark, V. similis and V. sulcata, are described with phylogenetic inference based on multiple loci (ITS1-5.8S-ITS2 and 28S). Volvariella similis is characterized by its brownish pileus, grey stipe without caulocystidia, clavate to broadly subutriform pleurocystidia, and cylindrical, tapering pileipellis elements. Volvariella sulcata is distinguished by its smaller basidiomata with a short stipe, sulcate-striate pileus margin, 35–45 lamellae, lageniform pleurocystidia with a long neck and pedicel, and a preference for man-made habitats. Comprehensive descriptions, illustrations, line drawings, and comparisons with morphologically similar and phylogenetically related species are provided.