Lingzhi, Ganoderma sichuanense, also known as reishi or Ganoderma lingzhi is a polypore fungus ("bracket fungus") native to East Asia belonging to the genus Ganoderma.
Its reddish brown varnished kidney-shaped cap with bands and peripherally inserted stem gives it a distinct fan-like 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 (80–120 μm) in yellow colors.
The lingzhi mushroom is used in traditional Chinese medicine. There is insufficient evidence to indicate that consuming lingzhi mushrooms or their extracts has any effect on human health or diseases.
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 rare. Lingzhi may be cultivated on hardwood logs, sawdust, or woodchips.
Lingzhi, also known as reishi from its Japanese pronunciation, is the ancient "mushroom of immortality", revered for over 2,000 years (with some evidence suggesting use in Neolithic China 6,800 years ago). However, as of 2023 there is an ongoing debate on which one of the described Ganoderma species is the lingzhi mushroom. It is also likely that a few different common species were considered interchangeable.
Under the scientific literature, the lingzhi mushroom is ambiguously referred to as:
Ganoderma sichuanense — the current name, described by Zhao and Zhang (1983).
Ganoderma lingzhi — described by Cao et al. (2012) as a novel species that is also the best fit for the traditional definitions of the lingzhi mushroom. However, Du et al. (2023) showed that it is the same species as G. sichuanense. It is now treated as a later synonym.
Ganoderma lucidum — a type species of Genoderma described by Karst (1881) based on the European population. Early records of chinese Genoderma populations identified them as G. lucidum, but it was later established that Asian populations are distinct from European both morphologically and phylogenetically.