Tuber melosporum smooth spores: an anomalous feature in the genus Tuber

This paper adds new insights on ecology and micromorphology of Tuber melosporum, a rare species with smooth spores. Eight T. melosporum ascomata collected in a 50 y old Pinus halepensis and Quercus ilex plantation in Sardinia, Italy, represent the first recovery of this species outside Spain. In comparison to the T. melosporum holotype, Italian specimens revealed differences in the number of spores in asci and spore shape. We propose an emended description of Tuber to include species without spore ornamentation.