Reishi Biochemistry
Ganoderic acid A, a compound isolated from Lingzhi.
Ganoderma lucidum produces a group of triterpenes, called ganoderic acids, which have a molecular structure similar to steroid hormones. Reishi also contains other compounds many of which are typically found in fungal materials including polysaccharides such as beta-glucan, coumarin, mannitol, and alkaloids.

Ganoderma lucidum, and its close relative Ganoderma tsugae, grow in the northern Eastern Hemlock forests. These two species of bracket fungus have a worldwide distribution in both tropical and temperate geographical regions, including North and South America, Africa, Europe, and Asia, growing as a parasite or saprotroph on a wide variety of trees. Similar species of Ganoderma have been found growing in the Amazon. In nature, Lingzhi grows at the base and stumps of deciduous trees, especially maple. Only two or three out of 10,000 such aged trees will have Lingzhi growth, and therefore its wild form is generally rare. Today, Lingzhi is effectively cultivated both indoors under sterile conditions and outdoors on either logs or woodchip beds.

Lingzhi is a polypore mushroom that is soft (when fresh), corky, and flat, with a conspicuous red-varnished, kidney-shaped cap and, depending on specimen age, white to dull brown pores underneath. It lacks gills on its underside and releases its spores through fine pores, leading to its morphological classification as a polypore.

Names for the lingzhi fungus have a two thousand year history. The Chinese term lingzhi ?? was first recorded in the Eastern Han Dynasty (25-220 CE). Petter Adolf Karsten named the genus Ganoderma in 1881.

Botanical names
The lingzhi's botanical names have Greek and Latin roots. The generic epithet Ganoderma derives from the Greek ganos ?a??? "brightness; sheen", hence "shining" and derma de?µa "skin". The specific epithet lucidum is Latin for "shining" and tsugae for "hemlock" from Japanese Tsug).
There are multiple species of lingzhi, scientifically known to be within the Ganoderma lucidum species complex and mycologists are still researching the differences among species within this complex.

The lingzhi mushroom or reishi mushroom (traditional Chinese: pinyin: língzhi; Japanese: reishi; Vietnamese: linh ch; literally "supernatural mushroom") encompasses several fungal species of the genus Ganoderma, and most commonly refers to the closely related species, Ganoderma lucidum and Ganoderma tsugae. G. lucidum enjoys special veneration in East Asia, where it has been used as a medicinal mushroom in traditional Chinese medicine for more than 2,000 years, making it one of the oldest mushrooms known to have been used medicinally. Because of lingzhi's presumed health benefits and apparent absence of side-effects, it has attained a reputation in the East as the ultimate herbal substance. Lingzhi is listed in the American Herbal Pharmacopoeia and Therapeutic Compendium.