Wild Guide: Oyster Mushrooms

Oyster Mushrooms

Pleurotus ostreatus

Status

Choice edible

Size

Cap width: 1–6 inches; stalk length: to 1¼ inches; stalk width: to ¾ inch

Distribution

Statewide

Oyster mushrooms grow in clusters year-round on the stumps, logs, and trunks of deciduous trees. The cap is shell-shaped and semicircular with smooth edges and a velvety texture. The flesh is thick and white. There are no lookalikes in Missouri that are poisonous. 

Human Connections

Oyster mushrooms are considered a prized culinary mushroom. People can grow them on coffee grounds and spent grain from beermaking. They are also being explored as a digester of inorganic waste and an environmentally responsible alternative to Styrofoam.

Life Cycle

The oyster mushrooms’ network of fungal cells — also called the mycelium — kills and eats plant parasites, known as nematodes, that damage plant roots. The nematodes provide the fungus with nitrogen, a nutrient that is otherwise difficult to break down in wood. This nematode-trapping ability is being studied as a possible biocontrol to prevent plant diseases caused by certain nematodes.