Five New Species of the Genus Hymenogaster (Hymenogastraceae, Agaricales) from Northern China.

In this study, five new species from China, Hymenogaster latisporus, H. minisporus, H. papilliformis, H. perisporius, and H. variabilis, are described and illustrated based on morphological and molecular evidence. Hymenogaster latisporus was distinguished from other species of the genus by the subglobose, broad ellipsoidal, ovoid basidiospores (average = 13.7 μm × 11.6 μm) with sparse verrucose and ridge-like ornamentation (1-1.2 μm high); H. minisporus by the ellipsoidal to broadly ellipsoidal and small basidiospores (average = 11.7 μm × 9.5 μm); H. papilliformis was characterized by the whitish to cream-colored basidiomes, and broadly fusiform to citriform basidiospores with a pronounced apex (2-3 μm, occasionally up to 4 μm high), papillary, distinct warts and ridges, and pronounced appendix (2-3 μm long); H. perisporius by the dirty white to pale yellow basidiomes, broad ellipsoidal to ellipsoidal, and yellow-brown to dark-brown basidiospores with warts and gelatinous perisporium; H. variabilis by the peridium with significant changes in thickness (167-351 μm), and broad ellipsoidal to subglobose basidiospores ornamented with sparse warts and ridges. An ITS/LSU-based phylogenetic analysis supported the erection of the five new species. A key for Hymenogaster species from northern China is provided.