Fibroporia vaillantii Fibroporia vaillantii Fibroporia vaillantii, also known as mine fungus, white pore fungus, Antrodia vaillantii, Polyporus vaillantii, and various other names is a wood-decaying fungus which can occur on timber in humid conditions. The fungus causes brown rot of pine wood, in which cellulose and hemicellulose are broken down, leading to brown discoloration and shrinkage of wood. It has been/is sometimes considered to be a fungus causing dry rot, although that term is more often used for wood decay due to a different fungus, "Serpula lacrymans". The fungus grows on wood from coniferous trees, such as pine wood, under damp conditions,
Serpula lacrymans environments, the Himalayas, Northern California, the Czech Republic and east Asia. A recent study on the evolutionary origin and spread of this species using genetic markers (amplified fragment length polymorphisms, DNA sequences and microsatellites) on a worldwide sample of specimens suggested the existence of two main lineages, a nonaggressive lineage found in North America, and an aggressive lineage found on all continents, both in natural environments and buildings. "Serpula lacrymans" is considered to be the most damaging destroyer of indoor wood construction materials in temperate regions. In the United Kingdom alone, money spent by building owners rectifying damage caused by