Peziza domiciliana, a cup fungus often referred to as the common indoor mushroom is usually associated with water-damaged buildings. “Domiciliana” means “around the house”. It has been found in a wide range of habitats including carpets in living rooms, shower stalls, damp closets, behind refrigerators, around leaky water beds, in cellars, greenhouses, under porches, damp walls, and even in cars. Peziza is the sexual state (or what mycologists call teleomorph) of this fungus. The asexual state (i.e., the anamorph) is called Chromelosporium. Just like Peziza, Chromelosporium can be found colonizing indoor surfaces of damp buildings. It’s also commonly found in soil, rotten or damp wood, humus, and garden compost. No information is available regarding health effects, toxicity, or allergenicity to humans.
Peziza domiciliana grows well on alkaline materials but can grow on anything that is porous and constantly moist such as wood, carpets, wallboard, furniture, fireplaces ashes, clothing, plaster, cement, sand, and coal dust. Mature Peziza domiciliana is a shiny yellowish tan inside and outside. Solitary cups are about 2 inches across or sometimes twice that. Often, a number of smaller, mutually compressed cups are found. These cup fungi have a rubbery texture and are large enough to pluck from carpets or baseboards with the fingers. If blown on with moist breath, spirals of faint puff of smoke composed of released ascospores can be seen.
Information regarding toxicity of Peziza domiciliana is currently not available but it is believed to be non-toxic. There are no reports of adverse health effects. Allergenicity has not been studied.
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