In China the species name Tuber californicum is assigned to pale truffles in the genus Tuber that have more or less regularly globose ascospores; however, we recently discovered that the name was misapplied to some specimens collected in China. In the present study we re-examined all available Chinese collections purported to be T. californicum, including herbarium specimens and newly collected materials, with morphological and molecular methods. The accessions separated into seven clusters in a phylogenetic analysis based on sequences of the internal transcribed spacers sequences of these materials. An ML tree generated with ITS, nuc 28S rDNA and translation elongation factor-1α sequences from Chinese and worldwide Tuber species with globose ascospores showed only two clades, the Puberulum clade and Latisporum clade. The Latisporum clade as recognized in this study includes the species known from eastern Asia only and probably represents a new lineage that arose in parallel with the Puberulum, Maculatum and Gibbosum lineages. We concluded that no evidence supports the existence of T. californicum in China and that the specimens misidentified as T. californicum belong to four species newly described herein, T. xuanhuaense, T. jinshajiangense, T. caoi and T. parvomurphium.

In phylogenetic analyses based on the internal transcribed spacers and 28S nuc rDNA and translation elongation factor 1-α to compare Chinese white truffle specimens that have ascomata resembling the European Tuber borchii, the sequences of Chinese species resembling T. borchii in morphology grouped into seven distinct clusters among three clades: Puberulum, Maculatum and Latisporum No sequences from these Chinese species matched those of the European T. borchii and the occurrence of the European T. borchii in China could not be supported by our study. Three unknown species are recognized from the seven Chinese clusters; two are described here as T. hubeiense and T. wumengense based on molecular and morphological evidence.