Ganoderma lucidum | Reishi Mushroom
LATIN NAME: Ganoderma lucidum
COMMON NAME: Reishi Mushroom (Ling Zhi)
Species Profile
Reishi is a bracket fungus, not a plant: a woody, kidney-shaped fruiting body with a lacquered, mahogany-red surface and a pale pore layer underneath. It grows on dead hardwood, and the slices sold for tea are cut from the dried fruiting body or from cultivated blocks.
The fungus is grown commercially on sawdust bags or on hardwood logs, and a crop takes two to four months from inoculation to harvest. Wild fruiting bodies are rare and are not a sustainable source, which is why almost all material in the trade is cultivated.
Ganoderma lucidum is found across eastern Asia, on the stumps of deciduous trees. It is one of the most studied medicinal fungi in the world, and the commercial market for it is measured in billions of dollars. Slices are graded by thickness, colour and the presence of the pale pore layer, and the grade matters more than the name on the packet.
Science & Biotechnology
The fruiting body contains beta-glucans, triterpenes such as ganoderic acids, and polysaccharides. The beta-glucans are the basis of the immune-modulating claims, and the triterpenes are the bitter compounds that give the tea its taste.
The evidence for the health claims is mixed. Some small trials suggest benefits for fatigue and for immune markers, while claims about cancer treatment are not supported by clinical evidence, and the fungus should not be used instead of conventional treatment.
Reishi also interacts with anticoagulants and with immunosuppressants, and it can cause digestive upset and, rarely, liver effects. The powder and the extract are not equivalent: the hot-water extract contains the polysaccharides, while the alcohol extract contains the triterpenes, and the two are sold for different purposes.
Uses & Benefits
Reishi is used as a tea, a powder and an extract, and it appears in Chinese formulas as a tonic. The slices are simmered for an hour or more to extract the polysaccharides, and the liquid is taken as a bitter drink.
In the garden the fungus is grown on logs and stumps as a crop and as a curiosity, and it is one of the easier medicinal fungi to cultivate. Commercially the market includes capsules, teas, extracts and cosmetics. It is not a culinary mushroom in the sense of something to fry.
Cultivation
Reishi is grown from spawn rather than from seed. Inoculate hardwood logs of oak, beech or maple by drilling holes and inserting plug spawn, then seal the holes with wax and keep the logs shaded and moist for a season while the mycelium colonises.
Alternatively, use supplemented sawdust blocks, which fruit in two to three months indoors at 21-24°C with high humidity. Harvest the fruiting bodies when the margin turns from white to the same colour as the cap, and dry them immediately at 40-50°C. Soak the log between flushes to trigger the next crop.
Our Take
A fungus rather than a plant, easier to grow on a log than most people expect, and best used as a bitter tea rather than a cure.
Related Reading
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