Merulius lacrymans is one of the wood-rotting fungi which are destroyers of trees, lumber, structural timbers and other forms of wood. Under certain conditions, this fungus is especially harmful to the wood in houses and for this reason it is known as the house fungus. The presence of fungi in wood is generally shown by a white floccose growth or mushroom-like sporophore on the exterior of the infected material. The house fungus announces its presence, only too late, by a cottony mass of hyphal threads spreading over the infected surfaces or emerging through cracks between walls and floors. This circular to elliptical cottony mass of hyphae grows to be about one centimeter thick when the surface begins to encrust, wrinkle and turn a rusty color due to the formation of rusty-colored spores.
Proceedings of the Iowa Academy of Science
©1924 Iowa Academy of Science, Inc.
Davis, W. H.
"The House Fungus, Merulius lacrymans (Jacq.) Fr.,"
Proceedings of the Iowa Academy of Science, 31(1), 169-173.
Available at: https://scholarworks.uni.edu/pias/vol31/iss1/38