Oyster mushroom

Oyster mushroom
Fruiting body of the Oyster mushroom in the Middlesex Fells Reservation. Fruiting body of the Oyster mushroom in the Middlesex Fells Reservation.
Conservation status
Secure
Scientific classification
Kingdom: Fungi Phylum: Basidiomycota Class: Homobasidiomycetes Order: Agaricales Family: Tricholomataceae Genus: Pleurotus Species: P. ostreatus
Binomial name
Pleurotus ostreatus Champ. Jura. Vosg. 1: 112, 1872

Pleurotus ostreatus mycological characteristics:   gills on hymenium 30px  30px  no distinct cap or offset 30px  hymenium is decurrent 30px  stipe is bare   spore print is white 30px  ecology is saprophytic 30px  edibility: choice

The Oyster mushroom, or Pleurotus ostreatus, is a common mushroom prized for its edibility and lack of confusing look-alikes. Long cultivated in Asia, it is now cultivated around the world for food. It is related to the similarly cultivated "king oyster mushroom". Oyster mushrooms can also be used industrially for mycoremediation purposes.

Name

Both the Latin and common name refer to the shape of the fruiting body. The latin pleurotus (sideways) refers to the sideways-growth of the stem with respect to the cap while the latin ostreatus (and the English common name, oyster) refers to the shape of the cap which resembles the bi-valve of the same name. Many also believe that the name is fitting due to the flavor resemblance to oysters.

In Chinese, they are called píng gū (平菇). Meaning "flat mushroom".

Identification

File:Oyster mushroom log.jpg

Oyster mushroom on a log.

The oyster is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media.

Cap

Size:5-25 cm broad, fan or oyster-shaped; Natural specimens range from white to gray or tan to dark-brown; margin inrolled when young, smooth and often somewhat lobed or wavy.

Flesh

Flesh white, firm, varies in thickness due stipe arrangement.

Gills and stem

Gills are white to cream, descend stalk if present. If so, stipe off-center with lateral attachment to wood.

Spores

The spores form a white to lilac-gray print on dark media.

Mycelium

The mycelium is white and grows rapidly.

Habitat

The Oyster Mushroom is wide-spread in temperate forests throughout the world. It is a saprophyte that acts as a primary decomposer on wood.

Edible uses

The oyster mushroom is frequently used in Japanese and Chinese cookery as a delicacy: it is frequently served either on its own, although sometimes stuffed: and in stir-fry recipes too with soy sauce.

Additional Information

Oyster mushrooms are a natural source of statin drugs. Studies have shown that they typically contain 0.4% to 2.7% statins on a dry weight basis. Z. Naturforsch Study. A number of studies on lab animals have shown that adding Pleurotus to the diet can reduce cholesterol under some conditions.

The oyster mushroom is also one of the few known carnivorous mushrooms. Its mycelia can kill and digest nematodes. This is believed to be a way to obtain nitrogen.

Oyster mushrooms contain a small amount of arabitol which can cause gastrointestinal distress in some people. Arabitol is a sugar alcohol similar to xylitol, manitol and sorbitol; these sugar alcohols are widely used food additives and can also have laxative effectives in susceptible individuals.

References

• Stamets & Chilton, The Mushroom Cultivator, 1983
• Stamets, Growing Gourmet and Medicinal Mushrooms (Third Edition), 2000
• National Audubon Society Field Guide to North American Mushrooms, 1997

See also

• Oyster sauce

External links

Wikimedia Commons has media related to:

Pleurotus ostreatus

• Culinary information regarding oysters
• The effect of Pleurotus ostreatus on cholesterol absorption
• General information including growing oyster mushrooms, market data, and more.bg:Кладница (гъба)