<i>Tuber eburneum</i> and <i>Tuber mujicii</i>: New pine-associated <i>Tuber</i> species from eastern North America

The ectomycorrhizal truffle genus <i>Tuber</i> is widespread and diverse. Recent sampling of ascomata, ectomycorrhizal root tips, and environmental sequences has resulted in the identification of many <i>Tuber</i> species that cannot be assigned to described species and require formal description. Using morphological and molecular phylogenetic analysis, we describe two North American <i>Tuber</i> species associated with pines (<i>Pinus</i> spp.). <i>Tuber eburneum</i>, sp. nov., is an early-diverging taxon in the Melanosporum clade that differs substantially from all other taxa in that clade due to its light-colored peridium and gleba, lack of peridial warts, and peridial hairs that are ornamented with small, irregular protrusions. <i>Tuber mujicii</i>, sp. nov., is a whitish truffle species in the Puberulum clade. Although <i>T. mujicii</i> is morphologically similar to many related taxa, it can be distinguished by a combination of characters, including peridium color, spore size, number of ascospores per ascus, and number of reticulations across the spore surface.