Russula nuda, a new species of Russula subsect. Xerampelinae (Russulaceae) from Japan

Abstract

A new species, Russula nuda, from Japan is described and illustrated. The species is characterized by a glabrous, white pileus with a pale brown center, a white stipe, a context that turns brown when bruised or dried, a pale olive reaction to FeSO₄, a fishy odor, and globose to ellipsoid basidiospores with numerous isolated warts. It grows in deciduous broadleaf forests dominated by Japanese beech (Fagus crenata). Maximum likelihood phylogenetic analyses were performed using an ITS dataset and an LSU-rpb2-tef-1a dataset. Based on morphological and molecular evidence, we place this new taxon within Russula subsection Xerampelinae.