Dry rot The term "dry rot", or "true dry rot", refers to the decay of timbers from only certain species of fungi that are thought to provide their own source of moisture and nutrients to cause decay in otherwise relatively dry timber. However, there has been no published experimental evidence to support the phenomenon. In modern texts, the term 'dry rot' is used in reference to damage inflicted by either: "Serpula lacrymans" (formerly "Merulius lacrymans") predominantly in the United Kingdom and northern Europe; and/or "Meruliporia incrassata" (which has a number of synonyms, including "Poria incrassata" and "Serpula incrassata") in North America. Both
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