oyster mushroom

Oyster mushroom
Fruiting body of the Oyster mushroom in the Havré wood Belgium.
Conservation status
Secure
Scientific classification
Kingdom:	Fungi
Phylum:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Tricholomataceae
Genus:	Pleurotus
Species:	P. ostreatus
Binomial name
Pleurotus ostreatus (Jacq. ex Fr.) Kumm.; Champ. Jura. Vosg. 1: 112, 1872

Pleurotus ostreatus
Mycological characteristics
	gills on hymenium
	cap is offset
	hymenium is decurrent
	stipe is bare
	spore print is white
	ecology is saprotrophic
	edibility: choice

The Oyster mushroom, or Pleurotus ostreatus, is a common edible mushroom. 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. The Oyster mushroom may be considered a medicinal mushroom due to the fact it contains statins such as lovastatin which work to reduce cholesterol.^[1]

Name

Details of the gill structure.

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; literally "flat mushroom"). In Vietnam, the mushroom is known as nấm sò or nấm bào ngư.^{[clarification needed]}

The oyster is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media. It often has the scent of anise due to the presence of benzaldehyde (which, however, smells more like almonds).^[2]

Description

Oyster mushroom on a tree.

The mushroom has a cap spanning 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 white, firm, varies in thickness due to stipe arrangement. The gills of the mushroom are white to cream, descend stalk if present. If so, stipe off-center with lateral attachment to wood. The spore print of the mushroom is white to lilac-gray, best viewed on dark background. The mushroom's stipe is often absent. When present it is short and thick. The taste of the mushroom is described as mild with a mild odor of anise.

There are no poisonous lookalikes that grow in North America^{[citation needed]}, however Omphalotus nidiformis is a toxic lookalike that is found in Australia and Japan.

Habitat

The Oyster Mushroom is widespread in temperate and subtropical forests throughout the world. It is a saprotroph that acts as a primary decomposer on wood, especially deciduous, particularly beech.^[3]

The mushroom usually is not fussy where it grows, however it does not like to grow near stinging nettles. This is probably due to the high acidity of the nettles. The oyster mushroom is also one of the few known carnivorous mushrooms. Its mycelia can kill and digest nematodes, which is believed to be a way in which the mushroom obtains nitrogen.

The standard oyster mushroom can grow in many places but some other related species such as the branched oyster mushroom grow on trees.

Edible uses

The oyster mushroom is frequently used in Japanese, Korean and Chinese cookery as a delicacy: it is frequently served on its own as soup, sometimes stuffed, or in stir-fry recipes with soy sauce. The mushroom's taste has been described as a mild with a slight odor similar to anise. The oyster mushroom is best when picked young as the mushroom ages the flesh becomes tough and the flavor becomes acrid and unpleasant.

Oyster mushrooms contain small amounts of arabitol, a sugar alcohol, which may cause gastrointestinal upset in some people.

Oyster mushrooms and lovastatin

In vivo research has shown that consumption of oyster mushrooms lowers cholesterol levels^{[4][5][6][7][8][9][10][11][12][13][14][15][16][17]}, which is due to the fact these mushrooms naturally contain lovastatin.^[1] Studies have shown that the mushrooms contain up to 2.8% lovastatin on a dry weight basis.^[18]

Gallery

See also

Medicinal mushrooms

References

• [Edible and Medicinal Mushrooms of New England and Eastern Canada] (2009) ISBN: 978-1-55643-795-3
• 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

External links

Wikimedia Commons has media related to: Pleurotus ostreatus

• Mushroom-Collecting.com - Oyster mushrooms
• The effect of Pleurotus ostreatus on cholesterol absorption
• [1]Dried shiitake (Lentinulla edodes) and oyster (Pleurotus ostreatus) mushrooms as a good source of nutrient.
• Time-lapse video of oyster mushroom growing to maturity
• Sremac bukovaca