Lingzhi mushroom

The lingzhi mushroom is a polypore mushroom belonging to the genus Ganoderma. Its red-varnished, kidney-shaped cap gives it a distinct appearance. When fresh, the lingzhi is soft, cork-like, and flat. It lacks gills on its underside, and instead releases its spores via fine pores. Depending on the age of the mushroom, the pores on its underside may be white or brown. Lingzhi mushroom is used in traditional Chinese medicine. In nature, it grows at the base and stumps of deciduous trees, especially that of the maple. Only two or three out of 10,000 such aged trees will have lingzhi growth, and therefore its wild form is extremely rare. Today, lingzhi is effectively cultivated on hardwood logs or sawdust/woodchips. It is part of a species complex that encompasses several fungal species. The most common and closely related species are Ganoderma lucidum (see also Scytalidopepsin B) and Ganoderma tsugae. There are multiple species of lingzhi encompassed within the Ganoderma lucidum species complex and mycologists continue researching the differences among species within this complex. Petter Adolf Karsten named the genus Ganoderma in 1881. English botanist William Curtis gave the fungus its first binomial name, Boletus lucidus, in 1781. The lingzhi's botanical names have Greek and Latin roots. Ganoderma derives from the Greek ganos (γανος; 'brightness'), and derma (δερμα; 'skin; together; shining skin'). The specific epithet, lucidum, is from Latin, meaning 'shining'. With the advent of genome sequencing, the genus Ganoderma has undergone taxonomic reclassification. Prior to genetic analyses of fungi, classification was done according to morphological characteristics such as size and color. The internal transcribed spacer region of the Ganoderma genome is considered to be a standard barcode marker. It was once thought that Ganoderma lucidum generally occurred in two growth forms: a large, sessile, specimen with a small or nonexistent stalk, found in North America, and a smaller specimen with a long, narrow stalk found mainly in the tropics. However, recent molecular evidence has identified the former, stalkless, form as a distinct species called G. sessile, a name given to North American specimens by William Alfonso Murrill in 1902. Environmental conditions play a substantial role in the lingzhi's manifest morphological characteristics. For example, elevated carbon dioxide levels result in stem elongation in lingzhi. Other formations include antlers without a cap, which may also be related to carbon dioxide levels. The three main factors that influence fruit body development morphology are light, temperature, and humidity. While water and air quality play a role in fruit body development morphology, they do so to a lesser degree. 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, growing as a parasite or saprotroph on a wide variety of trees. Similar species of Ganoderma have been found growing in the Amazon.