Tuber griseolivaceum sp. nov., a new olive-gray truffle species from China based on morphological and DNA data

Tuber griseolivaceum sp. nov. is described and illustrated from southwest China based on molecular and morphological analysis. Morphologically, the new species is easily confused with T. caoi because both have olive gray ascomata and regularly globose ascospores with reticulate ornaments, but T. griseolivaceum is distinguished from T. caoi by its blackish to black gleba and 3–4 (–5) meshes across the spore width. ITS-based phylogenetic analysis also strongly supports the erection of the new species.