Hypogeous Desert Fungi

Abstract

The term ‘desert truffle’ can be applied to multiple edible hypogeous fungi growing in arid areas throughout the world. Defining what a hypogeous fungus is, and what arid lands are, is hence critical to delimit this ecological group. We choose to define ‘hypogeous’ fungi as those species with closed or ‘sequestrate’ globose fruiting bodies growing totally under soil surface or partially covered by it. The terms ‘truffle’ and ‘tuberoid’ are applied to Ascomycetes species presenting asci, while ‘false truffle’ and ‘gastroid’ are preferred for Basidiomycetes, to highlight their evolution from ‘agaricoid’ habit, regarded in some cases as an adaptation to dry environments. The most prominent genera of desert truffles are mentioned, and keys are proposed for their identification within the Ascomycetes, Basidiomycetes, and the former Glomeromycetes. The most critical morphological traits used for these keys are briefly discussed, and some images to illustrate the criteria are provided.