Mushrooms That Can Grow Inside a House

Domicile Cup Fungus

• Domicile cup fungus (Peziza domiciliana), sometimes referred to as "the common indoor mushroom," is often found growing inside of houses behind refrigerators, in shower stalls, or along the baseboard of a carpeted hallway. Yellowish tan in color with a flat, pancake-like appearance, it has the ability to grow on a variety of surfaces, including plaster, cement, gravel and fireplace ash. It is a member of the class "Ascomycota." Domicile cup fungus thrives on moisture, and can grow to a diameter of 2 to 4 inches.

Inky Caps

• Small species of Inky caps (Corpinellus domesticus) are often found growing in damp bathrooms or basements. According to the Mushroom Expert website, this species of mushroom lays a "carpet" of bright orange fibers on damp substrates. Rafters and carpets are favorite places for Inky caps to colonize indoors. They have stems that are 1.5 to 4 inches long with caps that are 2 to 3 inches in diameter. Inky caps are honey yellow and white when young, and pale brown and gray when mature.

Oyster

• Oyster mushrooms (Pleurotus ostreatus) grow on wood in clusters that look like shelves. It is a whitish or cream colored mushroom with a 2- to 5.5-inch wide funnel-shaped cap. Stems are 4 to 8 inches long. Oyster mushrooms thrive in damp conditions on wood. According to Mushroom Expert website, it is sometimes found growing indoors on furniture or woodwork. It is an edible mushroom, with a scent that resembles anise.