Abstract
The fungal biodiversity of Central Asia, particularly within the vast pine forests of Kazakhstan, remains significantly under-studied. In this study, a new species, Russula viatica (Russulaceae), is described based on morphological and molecular evidence. The specimens were collected from Pinus sylvestris forests of the Kokshetau Hills. Taxonomically, R. viatica belongs to subgenus Brevipes, subsection Pallidosporinae. The new species is distinguished by its association with pine forests, an ochre spore print (Romagnesi IIIb), and subreticulate amyloid spore ornamentation, along with characteristic dimensions of basidia and basidiospores. An integrative taxonomic approach was employed, combining detailed macro- and microscopic examinations with phylogenetic analyses of ITS rDNA sequences. The results demonstrate that R. viatica represents a genetically distinct lineage, clearly separated from known Eurasian taxa. Detailed descriptions and illustrations are provided, and the phylogenetic position of the new species is discussed in the context of recent systematic revisions of the subgenus. Finally, to facilitate correct identification of similar taxa, a key to the Eurasian species of Russula subgen. Brevipes with dark spore prints is provided.