Tom Volk's Fungus of the Month for March 1999

This month's fungus is Ganoderma applanatum,the artist's conk

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Ganoderma applanatumThis month's fungus of the month is one that can be found nearly every state in the United States and every Canadian province at nearly every time of the year, Ganoderma applanatum. This species or its relatives also occur on just about every continent (except Antarctica, of course). It can be found all the time because it has a perennial, very hard fruiting body, one that adds new layers of pores every year.

Ganoderma applanatum is classified as a polypore, which literally means "many pores." The white pores are on the under-surface of the fruiting body. It is also known as a "shelf fungus" because the fruiting body forms a stalkless shelf on the sides of trees and logs. There are many, many species of shelf fungi, probably more than 500 species, so don't assume any shelf fungus can be classified here.

The Polypores are a fascinating group of fungi, although not usually of interest to most mycophiles because of their typical inedibility, commonly small size, unfamiliar habitat and general obscurity. However, these fungi are very interesting from an ecological, microscopic, and biotechnological standpoint, and are well worth observing and learning to identify. An added bonus from a collecting standpoint is that, unlike fleshy mushrooms, most of these fungi can be found even during dry weather or in the winter, since many are perennial and many others produce basidiocarps only beneath the surface of logs lying on the forest floor, where it remains wet most of the year. You'll never go home empty-basketed from a foray again! See this page for an introduction to polypores.

Polypores can be easily distinguished from the other common poroid fungi, the boletes, by their typically hard exterior, their usual "non-mushroom" shape, and growth on wood as wood decomposers. In addition the pore layer of boletes can usually be easily peeled off from the flesh (context).

Ganoderma sporesAt one time every fungus that was hard and had pores on the underside was classified in the genus Polyporus, but now there are more than 100 genera of polypore fungi. These genera are based on several kinds of characters:

  • what kind of hyphae are present in the fruiting bodies -- the hyphal system. Monomitic fruiting bodies contain one kind of hyphae, dimitic contain two and trimitic contain three.
  • Another important character is the type of rot, white rot vs brown rot. See this page for an explanation of the types of rot.
  • Spore characteristics such as type of wall, or reaction in Melzer's reagent (iodine)
  • simple septa vs clamps on the hyphae
  • many others.
For more information see my paper in the NAMA newsletter
Volk, Thomas J. 1998. Naming the Polypores: Why Polyporus has been split into more than 100 genera. MYCOPHILE 39(2):1-3.

Ganoderma lucidum with sporesGanoderma has its own genus because it has a dimitic hyphal system, causes a white rot, and has unusual brown spores with a double wall, as you can see in the picture above right. On the picture to the left you can see the enormous numbers of brown basidiospores that have been shed by the Ganoderma fruiting bodies. This is a common sight in the fall when the spores are dispersed by the wind to new substrates.

The species to the left is Ganoderma lucidum, which is an interesting story in itself. It is as hard as G. applanatum, but is annual rather than perennial. When not covered with spores it has a bright shiny reddish brown top surface and is rather beautiful. It is used in Oriental herbal medicine, where it is ground up and made into a tea, which is reported to cure everything from colds to impotence to AIDS. Like much oriental medicine, it must be taken over a long period of time to have it's desired effects-- very different from out western concept of medicine where we think it should take just a few pills to cure a disease or malady. Western medicine is slowly but surely discovering the wonders to be found in Oriental medicines made from fungi and herbs. Of course, most of the drugs used in western medicine came originally from fungi, plants, and bacteria, so there shouldn't be too much of a stretch in our imaginations here. But please don't write to me and ask about what medicines you should take for your particular malady-- I'm not a medical doctor.

Ganoderma applanatum But let's get back to Ganoderma applanatum -- why is it called the artist's conk? The conk to the right, drawn on by Nancy Korslin of the Wisconsin Mycological Society, shows why. When you scratch the white pores of the fruiting body, the white rubs away and exposes the brown hyphae underneath. A skilled artist can make some really incredible pictures. I don't think Nancy's online, but I also have some Ganoderma art done by another artist, Marie Heerkens. I don't have any of her conks scanned, but you can read more about this process and see more of her examples at Marie Heerkens' Mushroom Art Gallery.

I hope you enjoyed learning something about polypore systematics and especially about Ganoderma. It's an interesting fungus that can be found just about every time of year --- even in March in Wisconsin!

If you have anything to add, or if you have corrections or comments, please write to me at

This page and other pages are © Copyright 1999 by Thomas J. Volk, University of Wisconsin-La Crosse.

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