Fomitopsis officinalis (also known as Laricifomes officinalis) is probably the longest living mushroom in the world. Although this species was once widespread throughout the temperate regions of the world, it now grows almost exclusively in old growth forests of the Pacific Northwest of North America (in Oregon, Washington, and British Columbia), having become nearly extinct in Europe and Asia. Although it has been reported from China, it is now rare as a result of deforestation. Recent research has suggested that extracts from the mycelium of these mushrooms is active against pox, flu viruses, and pathogenic bacteria. (Stamets 2005)
Typically, this mushroom causes a top-rot in mature conifer trees, thereby providing essential habitat for cavity-dwelling animals. However, this slow-acting fungus is not an aggressive parasite and can often be found in trees hundreds of years in age. Once its host dies dies, the fungus can persist in the tree for several years as a saprophyte (i.e., feeding on dead organic material). (Stamets 2005)
