Wood-inhabiting fungi of the Białowieża virgin forest in Poland. XVIII. Amylocystis lapponica (Romell)Bond. & Sing

The author examined the microstructure of the fruitbody and culture of polypore Amylocystis lapponica (Romell) Bond. & Sing., common in the Białowieża virgin forest on lying logs of Picea excelsa with symptoms of advanced brown rot produced by Fomitopsis rosea (Alb. & Schw. ex Fr.) P. Karst. In the fruitbody a monomitic hyphal system was revealed consisting for the most part of thick-walled nodose-septate hyphae 4-10,5 μm thick. Moreover, by examination of four cultures obtained from basidiospores, it was found (1) that the diploid mycelium gives nearly always a negative reaction, whereas the haploid mycelia give positive reactions in tests for extracellular oxidase, and (2) that the fungus is tetrapolar.