Abstract:
The Leptographium olivacea complex encompasses species in the broadly defined genus Leptographium
(Ophiostomatales, Ascomycota) that are generally characterized by synnematous conidiophores. Most
species of the complex are associates of conifer-infesting bark beetles in Europe and North America.
The aims of this study were to reconsider the delineation of known species, and to confirm the identity
of several additional isolates resembling L. olivacea that have emerged from recent surveys in China,
Finland, Poland, Russia, and Spain. Phylogenetic analyses of sequence data for five loci (ACT, TUB,
CAL, ITS2-LSU, and TEF-1α) distinguished 14 species within the complex. These included eight known
species (L. cucullatum, L. davidsonii, L. erubescens, L. francke-grosmanniae, L. olivaceum, L. olivaceapini,
L. sagmatosporum, and L. vescum) and six new species (herein described as L. breviuscapum, L. conplurium,
L. pseudoalbum, L. rhizoidum, L. sylvestris, and L. xiningense). New combinations are provided for L. cucullatum,
L. davidsonii, L. erubescens, L. olivaceum, L. olivaceapini, L. sagmatosporum and L. vescum. New
Typifications: Lectotypes are designated for L. olivaceum, L. erubescens and L. sagmatosporum. Epitypes
were designated for L. olivaceapini and L. sagmatosporum. In addition to phylogenetic separation, the
synnematous asexual states and ascomata with almost cylindrical necks and prominent ostiolar hyphae,
distinguish the L. olivaceum complex from others in Leptographium.
