Pleurotus ostreatus (Jacq. : Fr.) P. Kumm. 1871
Grifola frondosa (Dicks. : Fr.) Gray 1821
Polyporus frondosus (Dicks. : Fr.) Fr. 1838 Note: Sanctioned by Fries
Syst. Mycol. I:355
Polypilus frondosus (Dicks. : Fr.) P. Karst. 1882
Cladodendron frondosus (Dicks.) Lázaro Ibiza 1916
Cladodendron frondosus (Dicks. : Fr.) Lázaro Ibiza 1916
Caloporus frondosus (Dicks. : Fr.) Quél. 1888
Merisma frondosum (Dicks. : Fr.) Gillet 1878
Cladomeris frondosa (Dicks. : Fr.) Quél. 1886
Boletus frondosus Dicks. : Fr. 1785
Agaricus ostreatus Jacq. : Fr. 1774 Note: Sanctioned by Fries
Syst. Mycol. I:182
Pleurotus limpidus (Fr.) Gill. 1887
Pleurotus salignus (Pers. : Fr.) P. Kumm. 1871
Pleurotus sapidus Kalchbr. 1887
Hen of the woods, oyster mushroom, gray oyster
These things can get big—really big. Salvatore Terracina, a farmer, encountered a specimen nearly 8' (2.4 m) in circumference, 20" (50 cm) thick, and weighing 42 pounds, near the north coast of Sicily! Typically these don’t exceed 8 inches in diameter. Oyster mushrooms are natives of North America, as well as temperate or subtropical forests throughout the world. They were first cultivated in Germany during World War I. The beautiful young cultivated ones shown here are courtesy of the Fat Moon Farm in Westford, Massachusetts. ”Oyster mushroom” also applies to several relatives, including but not limited to yellow oysters and pink oysters.
Identification: Oyster mushrooms grow out of the sides of trees, bending upwards so their caps are level, in thick clusters. The “stem” of each mushroom resembles the bell of a trumpet, with white parallel gills running along the length. (The “stipe,” or true stem, is not always visible; if visible, the base can be hairy.) Caps are tan or gray when young, becoming paler as they expand, and are typically 1½-6" (4-15 cm) in diameter. At first, they are more or less dome-shaped, but the dome flattens with age, becoming indented on the top or fan-shaped and wavy. They are quite variable in appearance. They favor hardwoods, both living and dead, but rarely appear on conifers as well. They appear from early Fall to mid-winter. Spore prints are whitish, lilac, or grayish.
Oyster mushrooms have a slight, characteristic odor likened to that of anise or bitter almonds, and due to the presence of a small amount of benzaldehyde.
Edibility: Oyster mushrooms don’t just look like their namesake, they taste a little like osyters too. They are frequently used in Japanese, Korean, Indian, and Chinese cuisine, and are rapidly growing in popularity in America as well. They are used in soups and stir-fry recipes. Here are a few recipes. They should be harvested young for eating.
Pleurotus ostreatus on Tom Volk's Fungi site, at the Department of Biology at the University of Wisconsin
Pleurotus ostreatus on Michael Kuo's MushroomExpert.com
Pleurotus ostreatus on Shroomery: Magic Mushrooms Demystified
Pleurotus ostreatus on Wikipedia
Pleurotus ostreatus on www.mushroom-collecting.com
Pleurotus ostreatus on Mykoweb.com: the Fungi of California
Pleurotus ostreatus on www.mssf.org
Pleurotus ostreatus description by Thomas H. Kent, last updated 25 May 2020.