Two New Species of Hymenogaster (hymenogastraceae, Agaricales) from China Based on Morphological and Molecular Markers

Two new species from China, Hymenogaster pseudoniveus and H. zunhuaensis, are described and illustrated based on morphological and molecular evidence. Hymenogaster pseudoniveus is distinguished from other species of the genus based on the color of peridium, which is snow white to white when unexcavated but then turns yellowish to earth yellow, and the basidiospores, which are ornamented with nearly longitudinally arranged ridges up to 2 μm high. H. zunhuaensis is diagnosed by its dirty white to pale yellow peridium, yellow brown to brown gleba, and the smaller (Lm × Wm = 11.7 μm × 9.8 μm) broadly ellipsoidal to subglobose basidiospores (Q = 1.1–1.3). ITS/LSU-based phylogenetic analysis supports the erection of the two new species, each placed in distinct clades with strong statistical support, suggesting that they represent two distinct species novel to science. Based on the morphological and molecular evidence, we have published two new species of Hymenogaster. A key for Hymenogaster species from China is provided.