The shiitake (Lentinula edodes) is an edible mushroom native to East Asia. It is generally known in the English-speaking world by its Japanese name, shiitake (kanji: lit. "shii mushroom," from the Japanese name of the tree that provides the dead logs on which it is typically cultivated).

In Chinese, it is called xiānggū (lit. "fragrant mushroom" or "delicious mushroom"). Two Chinese variant names for high grades of shiitake are dōnggū (Chinese: "winter mushroom") and huāgū "flower mushroom," which has a flower-like cracking pattern on the mushroom's upper surface); both are produced at colder temperatures. Other names by which the mushroom is known in English include Chinese black mushroom and black forest mushroom. In Korean it is called pyogo, and in Thai they are called hed hom.

The species was formerly known as Lentinus edodes and Agaricus edodes. The latter name was first applied by the English botanist Miles Joseph Berkeley in 1878.

History of cultivation
Shiitake mushrooms on a farm in Dongducheon, South Korea.This mushroom is native to China, and has been cultivated for over 1000 years. The first written record of shiitake cultivation can be traced to Wu Sang Kwuang, born during the Song Dynasty (960-1127 A.D.). However, some documents record the uncultivated mushroom being eaten as early as 199 A.D.

During the Ming Dynasty (1368-1644 A.D.), physician Wu Juei wrote that the mushroom could be used not only as a food but was taken as a remedy for upper respiratory diseases, poor blood circulation, liver trouble, exhaustion and weakness, and to boost qi, or life energy. It was also believed to prevent premature aging.

Culinary use
Shiitake have many uses in Chinese and Japanese cuisines. They are served in miso soup, used as the basis for a kind of vegetarian dashi, and also as an ingredient in many steamed and simmered dishes. In Thailand, they can be fried as well as steamed.

Shiitake are often dried and sold as preserved food in packages. These must be rehydrated by soaking in water before using. Many people prefer dried shiitake to fresh, considering that the sun-drying process draws out the superior umami flavour from the dried mushrooms by breaking down proteins into amino acids. The stems of shiitake are rarely used in Japanese and other cuisines, primarily because the stems are harder and take longer to cook than the soft fleshy caps.

Today, shiitake mushrooms have become popular in many other countries as well. Russia produces and also consumes large amounts of them, mostly sold pickled; and the shiitake is slowly making its way into western cuisine as well. There is a global industry in shiitake production, with local farms in most western countries in addition to large scale importation from China, Japan, and elsewhere.

Medicinal use
Shiitake mushrooms have been researched for their medicinal benefits, most notably their anti-tumor properties in laboratory mice. These studies, the earliest dating back to 1969, have also identified the polysaccharide lentinan, a (1-3) β-D-glucan, as the active compound responsible for the anti-tumor effects.[citation needed] Extracts from shiitake mushrooms have also been researched for many other immunological benefits, ranging from anti-viral properties to possible treatments for severe allergies, as well as arthritis.[citation needed]Lenthionine, a key flavor compound of shiitake, also inhibits platelet aggregation, so it is a promising treatment for thrombosis.[citation needed]

Shiitake are also one of a few known natural sources of vegan and kosher vitamin D (vitamin D2).