My Mushroom Dispensary

Guide · Shelf fungus · Family Ganodermataceae

Reishi

Ganoderma lucidum

A glossy, red-brown shelf fungus that looks as if it has been varnished. Reishi is too tough and bitter to eat as a vegetable, so for more than two thousand years it has been sliced and simmered into tea instead.

We grow and sell dried Reishi, $65 per pound.

Size
5–30 cm across
Cap
Glossy, red to brown
Underside
White pores, no gills
Grows on
Hardwood stumps and roots
Found in
Temperate and tropical forests worldwide
Used as
Tea, tincture, powder
A reishi mushroom with a glossy dark red cap and a pale growing edge Photo: Reishi with a pale growing edge
A growing cap. The white rim is new growth; it darkens as the cap matures.

Identify

How to recognize it

Reishi grows as a fan- or kidney-shaped shelf, usually on a short stem that attaches at the side. The top looks lacquered, with rings of red, orange and brown that get darker toward the stem. Its scientific name, lucidum, is Latin for shining.

  • Cap: glossy and hard, 5 to 30 cm across, red-brown with a white or yellow edge while growing.
  • Underside: a flat white surface covered in tiny pores, which bruise brown when scratched.
  • Stem: usually off to one side, the same varnished color as the cap. Sometimes absent.
  • Texture: corky when fresh, hard as wood when dry.
  • Spore print: brown. Mature caps are often dusted with their own brown spores.

Lookalikes

Several closely related Ganoderma species look nearly identical and have all been sold as reishi. Mycologists now treat the East Asian cultivated reishi as Ganoderma lingzhi, and the red reishi native to North America as G. sessile, G. curtisii and G. oregonense. Hemlock reishi (G. tsugae) grows on conifers. None are poisonous, and all are too woody to eat. Artist's conk (G. applanatum) is a dull grey-brown relative without the varnish.

Foraging safety: never use a wild mushroom unless an experienced forager or local mycological society has confirmed what it is.
A mature reishi mushroom with a deep red varnished cap Photo: mature Reishi cap
A mature cap, fully colored.
A young reishi with an orange and yellow cap and a white growing edge Photo: young Reishi
A young cap, still yellow and white at the edge.

Habitat

Where and when it grows

Reishi feeds on dead and dying hardwood. In the wild it grows at the base of trees, on stumps, and from buried roots, often returning to the same spot each year. Oaks, maples and plums are common hosts. It is found in temperate and tropical forests on every continent except Antarctica.

Fruiting bodies appear from early summer into fall. Because the flesh is so tough, an old cap can persist on its stump for months after it has stopped growing, slowly fading and collecting spores.

How it is grown

Cultivated reishi is grown on hardwood logs or on blocks of sterilized hardwood sawdust. Growers can shape the mushroom by controlling light and fresh air: in bright, well-ventilated conditions it forms the classic kidney-shaped cap, while in dim, still air it grows long finger-like "antlers" with no cap at all. Both forms are the same fungus.

A reishi mushroom growing from the base of a cherry tree Photo: Reishi on a cherry tree
Growing from the base of a wild cherry tree.
Several reishi caps growing together on the ground beside a tree Photo: a cluster of Reishi
A cluster fruiting from buried roots.

Preparing

In the kitchen

Reishi is bitter and as hard as bark, so it is never served as a mushroom dish. Its traditional use is a long, slow simmer that pulls the water-soluble compounds into a tea. The bitterness is normal; it comes from the same triterpenes people take reishi for.

Tea

  • Slice dried caps thin with a sharp, heavy knife, or break them into small chunks.
  • Add a small handful of slices to about a quart of water.
  • Simmer gently for one to two hours, topping up the water as needed, then strain.
  • Drink it plain or soften it with ginger, honey, cinnamon or a little lemon.
  • The same slices can be simmered a second time. Compost them after that.

Other preparations

  • Powder: a coffee grinder handles small dried pieces. Add it to broth or simmer it like the tea.
  • Tincture: many people soak reishi in alcohol and also simmer it in water, then combine the two. Follow a trusted recipe.
  • Storage: keep dried reishi in an airtight jar out of sunlight. It keeps for a year or more.
Thin dried slices of reishi mushroom Photo: dried Reishi slices
Dried reishi sliced for tea.

Research

Traditional use and research

Reishi is lingzhi in Chinese and reishi in Japanese. It appears in Chinese herbal texts going back about two thousand years, where it was prized enough to be called the mushroom of immortality and carved into art and furniture. It was rare in the wild, so until modern cultivation began in the 1970s it was expensive and mostly reserved for the wealthy.

Two groups of compounds get most of the attention: triterpenes, including the ganoderic acids that give reishi its bitterness, and beta-glucan polysaccharides from the cell walls. In lab and animal studies these affect immune cells and inflammation.

Human evidence is thin. Clinical trials have been small, short, and mixed, and systematic reviews have concluded there is not enough evidence to recommend reishi for treating any condition, including cancer. Most people tolerate it well; the most common complaints are dry mouth and an upset stomach. It may add to the effect of blood thinners and blood-pressure medicines, and a few cases of liver injury have been reported with powdered reishi products.

Talk to a doctor before using reishi if you are pregnant, take blood thinners or blood-pressure medication, have a bleeding disorder, or have surgery coming up.
Chinese name
Lingzhi
Japanese name
Reishi, mannentake
Other names
Varnished conk
Described by
Curtis; named by Karsten
Bitter compounds
Ganoderic acids
Also contains
Beta-glucans