07/17/2023
While studying forestry I was taught to call species of mushrooms within the genus Ganoderma, butt rot. Not a flattering name but considering the focus of most forestry practices is the value of timber, itâs kind of expected that these species would be viewed in a negative light. Some species of Ganoderma fall into the parasitic category of fungi. Meaning they attack and pe*****te the outer defenses of living organisms and use that organism for nourishment while causing disease and often death to the host. Other species of Ganoderma function more like saprotrophs. Saprotrophic fungi are the decomposes of the forest. Species within this category of fungi are more opportunistic and find their way into already dead and dying organic matter and break that matter down as they use it for nourishment.
There are around ten species of Ganoderma found in the southeastern United States. Some of these species are specialist, only occurring on specific host species. Ganoderma tsugae for example is only found on the Hemlock species, hence its speciesâ name Tsugae, which is the genus name of conifers that the Hemlock belongs to. This species of Ganoderma has an accepted common name, Hemlock Varnish Shelf, but it gets complicated with other species of Ganoderma when it concerns the use of common names.
The name Ganoderma is derived from Greek, gano meaning âbrightness, sheen" or âshiningâ and derma meaning âskinâ. With that understanding, one can look at any species of Ganoderma and see why this genus name was given. In general, they are red to reddish-brown and appear to have a polished surface. However, when it comes to common names for specific species, things get complicated. The oldest records of these mushrooms come from their use in Chinese medicine where they are commonly called lingzhi, or âmushroom of immortality.â Its use is documented for more than 2,500 years but is suspected to have been used for more than 4,000. However, in the West, weâve adopted the Japanese name, reishi as a broad term given to many species of Ganoderma.
Two commonly observed species in the southeast are G. curtisii and G. sessile. These two species are more saprotrophic and are not specialists. They can both be found on a few different tree species but are most commonly found at the base of oaks. Iâve found both at the foot of maples, plum trees, and pecan, but more so on water oaks than any other tree species. Luckily, there arenât any toxic lookalikes in the southeast United States, to my knowledge. Ganoderma curtisii was once believed to be in a close-knit complex of species that included the Asian variety but genetic testing has shown it to be a unique species. G. curtisii is commonly called Golden Reishi. Like other species of Ganoderma, Golden Reishiâs shape and size can vary due to growing conditions but typically they have a red to reddish-brown color with occasional purple hues showing up closer to and along the stem and increasing in golden colors toward the outer edges of the cap as it begins to form. These golden and white colors make their way to the very edge when it reaches maturity. Ganoderma sessile doesnât have an accepted common name but its scientific species name, sessile, gives insight into its appearance. Sessile means without a stalk or attached directly by the base. This species forms a shelf-like structure.
July and August are the two months of the year I find the most Ganoderma. So, while youâre out looking for chanterelles, keep an eye out for dead or dying oaks. There may be a mushroom of immortality growing at its base. Have you ever found a species of Ganoderma? Have you used it for medicine? Iâd love to hear about it!
