In our forum for technical questions, numerous clients have asked us about the differences among "varieties" and shapes of reishi, called deer horn shaped reishi, Japanese reishi, rokkaku reishi. We explain the differences among them here.
Real varieties of the reishi mushroom
To date, let us first say that, regarding biological varieties of reishi (Ganoderma lucidum), there are only three of these: Ganoderma lucidum var. nicotianae, published in the journal Sylloge Fungorum (England) in 1912. Ganoderma lucidum var. badium, described by Patoullardi in the mycological Bulletin of the Mycological Society of France, in 1899. Ganoderma lucidum var. resinosum, also found by the mycologist Patoullardi. None of these three varieties are cultivated, so we cannot say they are better or worse than the Ganoderma lucidum reishi type because there is no data to evaluate.
The varieties of reishi called Rokkaku Reishi, deer horn shaped reishi, or yoki reishi do not exist. There are currently only 3 varieties of Ganoderma lucidum, the ones already mentioned.
Throughout history, they have tried to obtain another 2 varieties of Ganoderma lucidum: Ganoderma lucidum var. orbiformis, which is currently considered a species itself but that belongs to another genus (Polyporus orbiformis). Ganoderma lucidum var. typicum, whose name is also invalid nowadays.
Two fruiting bodies of Reishi (Ganoderma lucidum variety Type). With and without developed cap. Picture of our crops.
Everything that is out of those varieties mentioned before, is simply marketing. Instead of varieties, they should be called ways of cultivation.
Growth forms of reishi regarding the cultivation method
The deer horn shaped reishi, also called Japanese Rokkaku Reishi, is a "normal" reishi which is forced to grow in "deer horns" shape. This way of growth is achieved in the crop by increasing the CO2 of the fruiting room and diminishing light: under these conditions, reishi does not develop his cap, it just forms branched stems with this characteristic hornlike shape. Currently, greater biological activity of this reishi is not proven, but it can be stated that they have less protein and less assimilable substances than a reishi grown with light and low levels of CO2, as we will explain later.
Why does the reishi with little CO2 and little light grow with "horn" shape? (growth forms designated as deer horn shaped reishi, antler shaped reishi or rokkaku reishi)
In nature, when Ganoderma lucidum bears fruit (the fungus that produces the reishi mushroom), it usually does that on buried wood or roots of trees. It very rarely bears fruit at the lower part of trunks of oaks or holm oaks, where other species do appear, such as G. pfeiferii (often confused with Ganoderma and collected for consumption, especially the pileated forms).
How does the fungus know when to form its cap? The fungus "checks" the CO2 and light where it grows: in the ground or inside the wood, there is more CO2 than outside, due to the fermentation of the organic matter, so inside the ground or inside the wood, it will grow with a stick or horn shape, until it comes out to the surface, where the concentration of CO2 is lower, and the mushroom develops his "cap". This is the strategy that the fungus uses to release its spores out in the open: if it developed the cap under the ground or inside the wood, it could not scatter its spores, as they would stay underground, but by developing the cap in the open air, the spores will spread successfully.
In a cultivation unit, growth can be forced so that reishi will never develop its cap, and this is achieved simply by increasing the CO2 concentration and diminishing light in the fruiting room, thus, the fungus is led to believe it is underground, and develops its growth in "horn" shape called deer horn shaped reishi in Japan, antler shaped reishi or Rokkaku Reishi: It is really Ganoderma lucidum bearing fruit in high CO2 concentration and low light conditions.
Is it better the deer horn shaped reishi growth form, Japanese reishi, than the reishi grown with a developed cap?
In research conducted on almost all the mushrooms, including the reishi, it can be observed that their caps have more proteins than the stems, and therefore the former are more digestible but less tough and resistant. This can be explained by the fact that the stem of a mushroom has the structural function: to grow the cap above the ground to be able to release the spores ("microscopic seeds") to the wind and being able to reproduce in another places. Thus the stem is more resistant than the cap (it has a greater support function) and this means that, in a chemical level, it has more structural carbohydrates (beta glucans) and fungal chitin compounds, which are indigestible but very tough. This higher percentage in fungal fibers leads to a lower protein content.
It happens the same with a meadow mushroom (Agaricus bisporus), that has a fibrous stem which is often removed before cooking, or a parasol mushroom (Macrolepiota procera) whose cap is huge, it’s all the same: we only eat the cap.
The "deer horn shaped reishi" consists of reishi stems with a “horn shape” and, consequently, they have the composition of a mushroom stem: they have fewer proteins than the cap and therefore less immunomodulatory proteins, and they will be less assimilated by the body too. In the end it is a less digestible product than the reishi grown under high oxygen and light conditions (normal growth). At a nutritional level, there are no studies that confirm that this growth form of reishi has higher properties than the normal reishi, in fact, it would be more correct to think otherwise.
Reishi fragmented for analysis of antioxidants and proteins. Own picture.
In nature, it is very difficult to find reishi shaped with this horn form because there are few places where high concentrations of CO2 are naturally met; we could locate it near wetlands in warm climates, where there is much fermentation activity and a lot of CO2 released, or places with high concentrations of organic matter and fermentation too (high CO2 content), near organic waste landfill sites, for example.