Asperosporus subterraneus, a new genus and species of sequestrate Agaricaceae found in Florida nursery production.

We describe a novel sequestrate genus and species, Asperosporus subterraneus gen. et sp. nov., found associated with nursery production of ferns in south Florida. This truffle species has a unique combination of morphological characters among described Agaricaceae in that it lacks a stipe or columella, has large, ornamented spores, the fresh sporocarps rapidly stain pink-red when cut or bruised, and they have a rancid smell. Although this fungus does not appear to be a direct plant pathogen, the hyphae of A. subterraneus produce a thick hydrophobic mycelial mat that binds the organic matter and therefore prevents water and fertilizer from being absorbed by plants, consequently causing wilting and chlorosis. Using morphological characteristics and phylogenetic reconstruction based on the internal transcribed spacer (ITS), partial large subunit nuclear ribosomal DNA (LSU), second largest subunit of RNA polymerase II (rpb2) and translation elongation factor 1-alpha (tef1) regions, we describe this taxon as a new genus and species in Agaricaceae.