Ophiostoma polonicum is a species of Ceratocystis sensu stricto

Ophiostoma polonicum was first isolated in Poland and described in 1939 by Siemaszko. The fungus is a serious pathogen of spruce and is vectored by the bark beetle Ips typographus. Ophiostoma polonicum was described as producing a Leptographium anamorph similar to that of Ophiostoma penicillatum. The fungus was later transferred to Ceratocystis penicillata but is currently treated as a species of Ophiostoma. Examination of the culture collected by Siemaszko and also from recent collections from spruce in Europe and Japan have shown the presence of a Chalara state. Cell polysaccharide analysis revealed the absence of rhamnose in the cells of O. polonicum which is more typical of Ceratocystis species. The fungus was also found to be sensitive to cycloheximide, which is characteristic of species of Ceratocystis sensu stricto. Comparisons of partial sequence data of the ribosomal DNA operon have also revealed that isolates of O. polonicum group together with Ceratocystis laricicola, which is a well defined species of Ceratocystis sensu stricto. We, therefore, conclude from this study that O. polonicum is a typical species of Ceratocystis s.str. and also that the species is very likely conspecific with C. laricicola.