The genus Otidea is one of the more conspicuous members of the Pyronemataceae, with high species diversity in hemiboreal and boreal forests. The genus is morphologically coherent and in previous higher-level multi-gene analyses it formed a highly supported monophyletic group. Species delimitation within Otidea is controversial and much confusion has prevailed in the naming of taxa. To provide a phylogenetic hypothesis of Otidea, elucidate species diversity and limits we compiled a four-gene dataset including the nuclear LSU rDNA and three nuclear protein-coding genes (RPB1, RPB2 and EF-1α) for 89 specimens (total 4 877 nucleotides). These were selected from a larger sample of material studied using morphology and 146 ITS (ITS1-5.8S-ITS2) and 168 LSU rDNA...
