|Peziza species are macrofungi commonly called cup fungi. One species in particular Peziza domiciliana is noted for growth on a wide range of domestic materials, including plaster, cement, sand, coal dust, wet rugs and carpets, fireplace ashes, and walls. It has been found in a wide range of locations, including carpets in living rooms, shower stalls, damp closets, behind refrigerators, around leaky water beds, in cellars, greenhouses, under porches, walls in school rooms, and in cars. 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 wispy smoke composed of released ascospores can be observed. Cup fungi are most closely related to elfin saddles (Helvella) and the morels (Morchella). Within this group are some of the most prized edible fungi. However, no specific information is available regarding toxicity of Peziza domiciliana but it is believed to be non toxic, and there are no reports of adverse health effects. Allergenicity has not been studied. Identification is made when the macro fungal bodies are collected and submitted. The ascospores of all these related fungi are somewhat distinctive and are identifiable on spore trap samples, especially when large fruitings are present within a building. Natural outdoor habitat for most species is soil, humus, or rotten wood. More information about these fungi is available in the book Mushrooms Demystified by David Arora, available at most local bookstores.