A rare and unusual lignicolous species of Inocybe (Agaricales) from eastern North America

Inocybe tubarioides is a rarely collected or recognized agaric with an unusual combination of ecological and morphological characters for this genus, namely a lignicolous habit and a strongly hygrophanous pileus. The species is known only from eastern North America and is reported here for the first time from states in New England and Canada. A taxonomic description is provided, including the first photographic record of the species and discussion of its evolutionary history. Based on molecular phylogenetic analysis the species is most closely related with significant measures of statistical support to two other narrowly endemic species of Inocybe: one also from eastern North America (I. tahquamenonensis) and another from northern Europe (I. relicina), the latter of which is the type of the genus Inocybe. These three species constitute the clade that corresponds with section Inocybe.