The versatile oyster mushroom has many synonyms, including tree oyster, pleurotus ostreatus, pearl oyster, and grey oyster. These names all refer to the same species of edible mushroom, known for its delicate, nutty flavor and velvety texture. Oyster mushrooms are popular in vegetarian and vegan cuisine, as they have a meaty quality that makes them a perfect substitute for meat in many dishes. They grow in clusters on dead or dying trees, and can be found in a range of colors from white or cream to light brown or grey. Whether you call them tree oysters or pearl oysters, these mushrooms are a delicious and healthy addition to any meal.