Calocybe kinabaluensis (Lyophyllaceae, Agaricales), a new species from Kinabalu UNESCO Global Geopark, Sabah, Northern Borneo, Malaysia

Abstract

Calocybe kinabaluensis sp. nov. was collected and described from Kinabalu UNESCO Global Geopark in Sabah, Malaysia. Morphological and phylogenetic evidence were used to delimit the collections as a new species. The species is characterized by its small to medium-sized basidiomata, deep blue to indigo-blue pileus with an irregularly lobed and undulate margin, and whitish to pale cream adnate to decurrent lamellae. Microscopically, it is distinguished by ovoid to broadly ellipsoid basidiospores, a cutis-type pileipellis, and the presence of cheilocystidia. Phylogenetic analyses of concatenated ITS and LSU sequences and ITS-only sequences distinguish this species from the molecularly closely related taxa, including C. cyanella and C. longisterigma. A detailed description and illustrations of the new species as well as comparative notes with other blue-capped taxa are provided. This research represents the first description of a new Calocybe species from Sabah, Malaysia, expanding current knowledge of the genus and highlighting the region as a significant area for future fungal diversity investigations.