Armillaria cepistipes is a common wood-rotting basidiomycete fungus found in most forests in Central Europe. Armillaria cepistipes is a species of mushroom in the family Physalacriaceae. This is a weakly plant pathogenic species that is typically found growing at the base of deciduous trees that have previously been stressed by another pathogen. The mycelium of the fungus is bioluminescent.