Tom Volk's Fungus of the Month for July 2000

three cheers for the red, white, and blue

This month's fungi are a patriotic trio of corticioid (crust) fungi, Phlebia coccineofulva, Hyphoderma puberum, and Pulcherricium caeruleum

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trio of partiotic fungi The 4th of July means Independence Day in the United States, so I picked some patriotic fungi to celebrate the occasion. This month's fungus is actually a trio of fungi. These are three of the most beautiful of the corticioid (kor-TISS-ee-oid) fungi, also known as the crust fungi or resupinate fungi. The corticoid fungi are actually very common, doing most of the work of decaying logs in the forest. You can find a wide variety of these crust fungi if you start turning over logs and looking at their undersides. There, in the moist area under the log, you will find fruiting bodies, which are not like most fruiting bodies (e.g. mushrooms) you may already know. Mushrooms are formed to raise the basidiospores for reproduction above the substrate so that the spores can be dispersed as far as possible, usually by the wind. The crust fungi have no such elaborate structures, but compensate by having their fruiting bodies remain active from early spring to late fall. many of them are able to dry out ad rehydrate, which most mushrooms cannot do. The fruiting body of a crust fungus consists only of a thin layer or hyphae (called a subiculum [suh-BIK-you-lum]) on the surface of the log with a layer of basidia to the outside. These basidia, which always point downward, form and disperse the spores. Of course the fruiting bodies shown here are placed upside down for photographing. Most corticioid fruiting bodies are not so beautiful, but they make up for it by having very unusual and beautiful microscopic characteristics. most of them are white or tan, but there are lots of color variations, including bright yellow, green, orange, purple and the colors shown here.

Phlebia coccineofulva The first of these fungi is Phlebia coccineofulva (FLEE-be-uh kok-sin-ee-o-FOOL-va), a rather common, though rarely seen, fungus in our part of Wisconsin. Phlebia is a genus of fungi with waxy basidiocarps with closely adherent basidia. "Coccineo-" refers to the scarlet red fertile layer and "fulva" refers to the yellow subiculum underneath it. A very striking and beautiful fungus indeed! You can see in the lower part of the photograph that the fruiting body becomes duller with age, and dried specimens are quite ordinary looking, lacking the red and yellow colors. This is one fungus you certainly want to see fresh.

There are many other species of Phlebia, but I think this is the most beautiful of them. Karen Nakasone at the Forest Products Lab in Madison, Wisconsin (where I used to work) is working on the species of Phlebia, and her broad (and widely accepted) concept of the genus includes some species that are flat or somewhat warty like this, some with folds (P. incarnata), some with pores (P. tremellosa) and even some with teeth (P. uda and P.setosa)!

Hyphoderma puberum Here's a very typical looking white corticioid fungus. It could be just about anything, but we believe it is Hyphoderma puberum (hi-fo-DERMA-uh PUBE-er-um). Hyphoderma means hyphal skin and puberum refers to the large cystidia that make the surface of the fruiting body look pubescent under a hand lens. Many of the fungi you find when turning over logs are this nondescript color. However when you look at them in the microscope they are nothing alike. Some have really huge or strangely ornamented spores, some have bizarre crystals, and some have spectacular cystidia. most of them are worth a good look or two. One of these nondescript white corticioid fungi, Phanerochaete chrysosporium has the potential for use in biopulping and bioremediation. Take the link to learn more about this fungus.
Pulcherricium caeruleum I consider Pulcherricium caeruleum (pull-chair-ISS-ee-um sa-RULE-ee-um) to be the most beautiful of the corticioid fungi (although Phanerochaete chrysorhizon could give it a run for its money in a fungal beauty pageant... [You may begin singing "Ohhhhh, here she comes,... Miss Corticioid]). Pulcherricium means "most beautiful" and caeruleum means blue. Pictures do not really do it justice at all. In real life it looks like someone coated a stick with blue velvet. The color shown here is pretty close to its natural color, although this specimen (from western North Carolina) is a bit darker than the above specimen (from central Missouri). Those are the only places I've ever seen it, but I believe it's more widespread than that. Have you seen it in your area?

I hope this page has encouraged you to turn over a few logs while you're out in the woods. You're almost certain to find some sort of resupinate fungus on the underside of the log. There are several hundred different species in more than 100 genera. If you have a microscope, I would suggest you take the fungus home and examine it. You might be surprised what you find! An added advantage of collecting resupinate fungi is that you are almost never "skunked" on your fungus foray-- the undersides of logs remain moist long after everything else has dried out. You just might find something beautiful where you least expect it.

Special thanks for this month's fungi goes to my friend and former student Daniel Ludwig Lindner Czederpiltz (now in graduate school in Plant Pathology at UW-Madison), whose idea it was to put these three fungi together at a foray last year. Thanks Dan!

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 2000 by Thomas J. Volk, University of Wisconsin-La Crosse.

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