Wood-decay fungus fungi of certain types remove cellulose compounds from wood and hence the wood becomes brown colour. Brown rot in a dry, crumbly condition is sometimes incorrectly referred to as "dry rot" in general. The term "brown rot" replaced the general use of the term "dry rot", as wood must be damp to decay, although it may become dry later. Dry rot is a generic name for certain species of brown-rot fungi. Brown-rot fungi of particular economic importance include "Serpula lacrymans" (true dry rot), "Fibroporia vaillantii" (mine fungus), and "Coniophora puteana" (cellar fungus), which may attack timber in buildings. Other brown-rot
Serpula lacrymans needed to promote "Serpula lacrymans" growth. In terms of aeration "Serpula lacrymans" often grows near ventilation shafts which shows a preference for concentrated oxygen. A moisture content of 30 to 40 percent is its ideal level in wood to promote fruit body formation. It appears that "Serpula lacrymans" requires an environment where both inorganic and organic materials are present. The fungus uses calcium and iron ions extracted from plaster, brick, and stone to aid the breakdown of wood, which results in brown rot. Although it is a common indoor biodeterioration agent, it has only been found in a few natural