RESUMO
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.
RESUMO
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.