Dry rot species of fungi cause brown rot decay, preferentially removing cellulose and hemicellulose from the timber leaving a brittle matrix of modified lignin. The term "dry rot" is somewhat misleading, as both species of fungi "Serpula lacrymans" and "Meruliporia incrassata" require an elevated moisture content to initiate an attack on timber (28–30%). Once established, the fungi can remain active in timber with a moisture content of more than 20%. At relative humidities below 86 percent, growth of "Serpula lacrymans" is inhibited, but it can stay dormant at relative humidities down to 76 percent. These relative humidities correspond to equilibrium moisture contents
Serpula (fungus) Serpula (fungus) Serpula is a genus of fungi in the family Serpulaceae. The term was originally defined by Christiaan Hendrik Persoon as a section of the genus "Merulius" in 1801. British botanist Samuel Frederick Gray raised it to genus status in his 1821 work "The Natural Arrangement of British Plants". The name is derived from the Latin verb "serpěre" "to creep". Synonyms include Johann Heinrich Friedrich Link's 1809 "Xylophagous", Christian Hendrik Persoon's 1825 "Xylomyzon", Narcisse Théophile Patouillard's 1874 "Gyrophora", and Patouillard's 1897 "Gyrophana". "Serpula" forms a clade with at least two other closely related genera, "Austropaxillus" and "Gymnopaxillus", the three