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 (fungus) composing the family Serpulaceae. It is thought that the common ancestor was saprotrophic,and that ancestor to the latter two genera became mycorrhizal. Using molecular clock analysis, the split between "Austropaxillus" and "Serpula" has been estimated to have occurred about 34.9 mya, roughly coinciding with the separation of South America and Australia from Antarctica. The number of species is uncertain – the two species "S. lacrymans" and "S. himantioides" have been considered to be a single species, or the latter species has possibly five cryptic species within its complex. The members of the genus "Serpula" form flat brown fruit bodies that