Integrative taxonomy reveals two new species of Cortinarius section Telamonia (Cortinariaceae, Agaricales) from southwestern China.

Cortinarius is renowned for its extraordinary species richness and cosmopolitan distribution. During a recent survey of macrofungal diversity across the Qinghai-Xizang Plateau, four specimens morphologically assignable to Cortinarius were collected. Based on detailed morphological characteristics and molecular phylogenetic analyses, these specimens are herein described as two new species within Cortinarius sect. Telamonia. Cortinarius linzhiensis, collected from mixed forests of Quercus and Picea, is characterized by a weakly hygrophanous, wrinkled pileus surface, a margin retaining spiderweb-like veil remnants, and a stipe apex occasionally exhibiting a pale violet tint. Cortinarius pallidomarginatus, collected from subtropical broadleaved forests dominated by Castanopsis, Lithocarpus, and Cyclobalanopsis, is characterized by its reddish-brown pileus with a contrasting white margin. This study provides detailed morphological descriptions, illustrations, and phylogenetic evidence supporting the recognition of these two novel taxa, along with comparisons with closely related species.