Serpula (fungus) cover the surface they are growing on (known as the substrate). The hymenophore, or spore-forming surface, generally has a wrinkled appearance. The species grow on, and digest, mainly coniferous wood, causing a process known as brown rot. One species, dry rot ("S. lacrymans"), is a highly destructive agent of houses. Damp structural timber is an ideal substrate for the germination of "Serpula" spores. The fungal hyphae penetrate the wood and release enzymes that break down structural polysaccharides such as cellulose. There may be no external indications that the fungus is present until the rot is far advanced and fruit bodies
Serpula himantioides appear as distinctive fruiting bodies on the exterior of the host. "S. himantioides" prefers the moist wood of coniferous hosts such as fir, larch, spruce, and pine. It is the causal agent of butt rot disease, the symptoms of which include rotting the heartwood at base of tree, as well as damage to the tap root and cores of lateral roots, but standing trees show no signs of infection. It also a common cause of timber rotting in buildings, which has made this pathogen difficult to differentiate from "S. lacrymans" because of their similarities. This disease often goes unnoticed initially