Two new Inosperma (Inocybaceae) species from the karst forest of Guangxi, China

In this study, we described two new species, Inosperma nonggangense Y. G. Fan, G. F. Mou & S. Li, sp. nov. and Inosperma rufobrunneum Y. G. Fan, G. F. Mou & S. Li, sp. nov. from Guangxi, China. These species were identified based on morphological and multi-locus (ITS, LSU, and rpb 2) phylogenetic analyses. Inosperma nonggangense sp. nov. is characterized by yellowish to orange basidiomata, rimulose pileus, crowded lamellae, ovoid to ellipsoid basidiospores measuring 8.7–9.9 × 5.2–6.1 μm, thin-walled, broadly clavate cheilocystidia, and abundant oily hyphae in hymenophoral, pileal, and stipe trama.

Inosperma rufobrunneum sp. nov. is characterized by reddish-brown basidiomata at maturity, rimulose to rimose pileus, crowded lamellae, nearly smooth stipes, ellipsoid basidiospores measuring 8.2–9.3 × 4.9–5.4 μm, and thin-walled, clavate cheilocystidia. Phylogenetically, these species belong to the Old World tropical clade 2, formed distinct independent lineages.