The genus Micropsalliota is a group of saprotrophic mushrooms, characterized by small to medium-sized basidiomata with fibrillose-squamulose or glabrous pilei, ellipsoid to amygdaliform or cymbiform basidiospores and cheilocystidia that vary in shape from clavate to ventricose or lageniform with more or less a capitate apex. In this study, we described a new species of Micropsalliota from southern Oman. Species description is based on morphological features of basidiomata and phylogenetic analyses of nuc ribosomal DNA internal transcribed spacer (ITS) and D1–D2 domains of the 28S region. The new species Micropsalliota ventricocystidiata is characterized by a medium-sized basidiomata, with plano-convex pileus, covered with reddish-brown squamules and basidiospores are ellipsoid to amygdaliform with acute apex in side view and oblong in face view, measuring 7.5–8.5 × 4.5–5 µm. Morphological comparison of M. ventricocystidiata with respect to other species of the genus is provided. We discussed that species of the genus can be divided into two groups based on their pileus morphology and basidiospores size.

Xanthagaricus is a saprotrophic mushroom genus with small-sized basidiomata in the family Agaricaceae (Agaricales). Prior to this study, 26 species belonging to this genus have been described and published. In this study, we reported Xanthagaricus for the first time from Oman with the description of two new species. Basidiomata of the new species Xanthagaricus appendiculatus and X. omanicus were collected during the monsoon rains of summer in 2018 in the southern coastal region of Oman. Species descriptions are based on morphological and molecular characterization. Phylogenetic analyses based on internal transcribed spacer region (ITS1-5.8S-ITS2 = ITS) of the nuclear ribosomal DNA clustered the new species in the Xanthagaricus clade with strong statistical support. The new species Xanthagaricusappendiculatus can be distinguished from other species by its purplish pileus with umbonate disc and X. omanicus with the largest pileus (70–90 mm diameter) among the known species of the genus. A detailed description, photographs, line drawings, and a phylogenetic tree showing the position of both new species are provided. A dichotomous key to the known taxa of Xanthagaricus is proposed. Morphological comparisons of new species with known Xanthagaricus taxa are provided. Our observations highlight the diversity of Xanthagaricus and other lepiotaceous mushrooms in southern Oman and further document the need for additional systematic focus on the region’s fungi.

Fuscoporia is a large genus with approximately 80 known species, distributed in various climates from subtropical to temperate, across the all continents except Antarctica. Divergence times of Fuscoporia was estimated for the first time, using BEAST v. 1.8.4, with three internal calibration points. Using three DNA regions: internal transcribed spacers (ITS1-5.8S-ITS2 = ITS), D1/D2 domain of large subunit of nuclear ribosomal DNA (28S) and translation elongation factor 1 alpha gene (TEF1α), the ancestral age of the genus was estimated around 77 Myr (million years). Molecular clock analyses also indicate the presence of six major clades, and the stem ages of each were estimated below 50 Myr. These six clades could be used for infrageneric classification of Fuscoporia. Further, we also discussed the distribution of Fuscoporia species in various climates. We hypothesized that the ancestral species of the genus evolved during late Cretaceous period with resupinate fruiting body in subtropics of Southern Asia. Furthermore, we also described a new species in the genus, Fuscoporia dhofarensis from Dhofar region, located in the southern part of Oman. Species description is based on morphological characteristics of fruiting body and phylogenetic analyses of ITS, 28S and TEF1α regions. The new species is characterized by a pileate fruiting body, with dimitic hyphal system, broadly ellipsoid basidiospores.