Not worth eating
Reishi, lingzhi
Ganoderma lucidum, G. tsugae and relatives
The character that does the work
A varnished red-brown bracket that looks as though it has been french-polished.
The specimen sheet, in examination order
01Cap
5 to 25 cm, kidney-shaped, varnished and glossy as if lacquered, deep red-brown with a paler growing margin.
02Underside
Fine white pores, bruising brown.
03Stem, and the base
Often present and lateral, dark and varnished.
04Flesh, cut
Corky and hard. It is wood, not food.
05Spore print
Brown to rust
How to take one06Where it grows
On hardwood stumps, or on hemlock in the case of G. tsugae.
When to look
Typically Jun to Oct in the northern hemisphere. Fruiting swings by weeks with rainfall and by a month or more with latitude, so this is when to look rather than when it will be there.
Northern hemisphere, as a species complex that is still being untangled.
What is worth knowing about it
Too hard to eat and used as a bitter decoction. It has been part of Chinese medicine for two thousand years and is now sold worldwide on the strength of clinical claims that run well ahead of the evidence. What the trials actually show is set out on the functional mushrooms page, without either the marketing or the dismissal.
Confused with
- Other Ganoderma species, none dangerous
In the kitchen
Not a food. Simmered for hours to make a bitter tea, or extracted in alcohol.
The techniques, and why they workGrowing it
Sold as a supplement
Two thousand years of recorded use, a great deal of laboratory work, and human evidence that stays stubbornly thin. It is the mushroom where the gap between reputation and demonstration is widest.
The claims, graded by what the evidence actually isThis page tells you what to check. It does not tell you the mushroom in your hand is that species, and it cannot. If you are not certain, do not eat it. If you have already eaten something and feel unwell, contact a poison centre and keep an uncooked specimen.
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