October 9th, 2010


50 More Urban Species #41: Reishi

Reishi Ganoderma lucidum

Identifying mushrooms is difficult, perhaps I've mentioned that before. Many species look similar to one another, and many field markings are variable. In G. lucidum what appears to be a bracket fungus, growing directly from a tree here, can have a long stalk. It can be relatively more red, or banded like a candy corn, or more white. It can be broad and fan-like, or narrow and branched like antlers. All of this would be mere curiosity for naturalists if this mushroom wasn't among the most important medicinal fungi in traditional Asian medicine.

The shape and perhaps the color, as well as other attributes are thought to enhance one property or another. Fortunately scientists are starting to look into it, and are finding anti-tumor and other protective qualities. Whether the shape of the mushroom influences its ability to cure disease is not known, but it is known that the shape is influenced by the conditions of the mushroom's growth. Longer reishi mushrooms and stalked fan-like brackets tend to be produced in warmer areas. In Boston we tend to see stalkless brackets on trees and misshapen blobs growing from hidden roots. One of these latter mushrooms was treated with great suspicion in New York City recently. Hacked from its spot where it was growing on subterranean Callery pear roots, it grew back; well, of course it did--removing the fruiting body does practically nothing to the fungus that produced it.

Reishi (I'm using the Japanese name because it is short and easy to say) can be a beautiful and durable mushroom. If you don't grind it up for tea you can dry it and keep it as an ornament. It readily grows in cultivation and you can buy kits to do so. (You can also buy capsuled reishi supplements and even reishi-infused chocolates.) In North America, a close relative G. tsugae grows from conifers. DNA research seems to indicate that the two North American species are closer related to one another than they are to the G. lucidum that grows in Asia. The above specimens are growing from a larger burl on a honey locust tree that has appeared in this journal (here) before. I posted a very different photo of mushrooms from this species complex here.