New North American truffles (Tuber spp.) and their ectomycorrhizal associations

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.\ud This is the publisher’s final pdf. The published article is copyrighted by The Mycological Society of America and can be found at: http://www.msafungi.org/.Recent surveys of belowground fungal biodiversity in Mexico and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the Maculatum group, an understudied clade of small truffles with little apparent economic value. These species are among the more taxonomically challenging in the genus. We collected Tuber castilloi, T. mexiusanum and T. guevarai as fruit bodies and ectomycorrhizae on Quercus spp. in forests of eastern Mexico. Tuber mexiusanum has a particularly broad geographic range, being collected in eastern USA under Populus deltoides and in Minnesota and Iowa in mixed hardwood forests. T. walkeri is described from the upper midwestern USA, and T. lauryi and T. beyerlei occur in the western USA