Historical biogeography and diversification of ringless Amanita (section Vaginatae) support an African origin and suggest niche conservatism in the Americas.

Ectomycorrhizal fungi (ECM) sustain nutrient recycling in most terrestrial ecosystems, yet we know little about what major biogeographical events gave rise to present-day diversity and distribution patterns. Given the strict relationship between some ECM lineages and their hosts, geographically well-sampled phylogenies are central to understanding major evolutionary processes of fungal biodiversity patterns. Here, we focus on Amanita sect. Vaginatae to address global diversity and distribution patterns. Ancestral-state-reconstruction based on a 4-gene timetree with over 200 species supports an African origin between the late Paleocene and the early Eocene (ca. 56 Ma). Major biogeographic "out-of-Africa" events include multiple dispersal events to Southeast Asia (ca. 45-21 Ma), Madagascar (ca. 18 Ma), and the current Amazonian basin (ca. 45-36 Ma), the last two likely trans-oceanic. Later events originating in Southeast Asia involve Nearctic dispersal to North America (ca. 20-5 Ma), Oceania (Australia and New Zealand; ca. 15 Ma), and Europe (ca. 10-5 Ma). Subsequent dispersals were also inferred from Southeast Asia to East Asia (ca. 4 Ma); from North America to East Asia (ca. 11-8 Ma), Southeast Asia (ca. 19-2 Ma), Northern Andes (ca. 15 Ma), and Europe (ca. 15-2 Ma), respectively; and from the Amazon to the Caribbean region (ca. 25-20 Ma). Finally, we detected a significant increase in the net diversification rates in the branch leading to most northern temperate species in addition to higher state-dependent diversification rates in temperate lineages, consistent with previous findings. These results suggest that species of sect. Vaginatae likely have higher dispersal ability and higher adaptability to new environments, in particular compared to those of its sister clade, sect. Caesareae. Overall, the much wider distribution of A. sect. Vaginatae, from pan-tropical to pan-arctic, provides a unique window to understanding niche conservatism across a species-rich clade of ECM fungi.

Lentinula ixodes comb. nov. (Omphalotaceae, Agaricales) including new records in Brazil.

In the search for new strains of edible mushrooms in the Brazilian Amazon Forest, we found Lentinula specimens different from Lentinula raphanica. These were described morphologically and evaluated phylogenetically within the Lentinula clade. The mating system was determined, and interbreeding compatibility with L. raphanica was verified. The basidiomata have a cinnamon or deep orange to fulvous brown, moist to dry pileus, occasionally with whitish scales; crowded whitish cream lamellae; and an eccentric to lateral stipe. The typical, predominant basidiospores are 4.4-7.2 µm in length. Endogenous, elongate (7.8-14 µm) basidiospores were also found in some specimens. The long spores seem rare and occasional, but nonetheless a novelty for the group. Basidia are homogeneous in size, cheilocystidia are pyriform or bulboid, and caulocystidia are long and spheropedunculate. The hyphae of the pileipellis are pigment-encrusted. The characteristics match those of Agaricus ixodes originally described from Guyana, currently a synonym of Lentinula boryana. In the phylogenetic trees, such taxon appears distinct from L. boryana and sister to L. raphanica with strong support. This unique lineage was confirmed to be reproductively isolated from sympatric L. raphanica strains. Lentinula ixodes comb. nov. is the second species of the genus reported in the Amazon Forest.

The Amazonian luminescent Mycena cristinae sp. nov. from Brazil.

A new luminescent lignicolous fungal species, Mycena cristinae sp. nov., is proposed from the Central Amazon forest. This is unique and supported by morphological evaluation along with LSU- and ITS-based phylogenetic analyses. The basidiomata have mostly fuscous olivaceous brown pileus, adnate to subdecurrent and distant lamellae, and stipe with slightly bulbous base (basal mycelium absent). It also has inamyloid and/or weakly amyloid basidiospores, ramose cheilocystidia and a pileipellis composed of an aerated tangle of slender, diverticulate hyphae forming a coralloid pellicle overlaying the hypodermium. The luminescence is evident in the basidiomata (especially the stipe) and in the mycelium on the substrate. The LSU phylogenetic trees reveal that M. cristinae is sister to M. coralliformis within the Mycenaceae clade. In the ITS trees, it forms a unique lineage grouping with undetermined Mycena taxa. Morphological data support M. cristinae as a different species compared to previously described taxa.