Tom Volk's Fungus of the Month for February 2001

This month's fungus is Climacodon septentrionale, the northern tooth fungus. This is my 50th Fungus of the Month!

For the rest of my pages on fungi, please click

Climacodon septentrionale overlapping clustersThis month's fungus is an interesting parasite of trees, predominantly maple trees, and especially sugar maple, Acer saccharum. The fungus causes a heartrot of the tree (growing in the central heartwood) often weakening the tree enough so that strong winds can snap the trunk and blow it over. The only outward signs of the fungus are the shelf-like fruiting bodies that are produced in large overlapping clusters. The mushroom is not known to be poisonous, but it is bitter and too tough to eat. It can be very exciting when you sight this fungus from several hundred feet away, thinking it's a large cluster of oyster mushrooms, but when you finally get close enough to see the teeth it's a major disappointment to find it's *only* the northern tooth fungus. However, if you're looking in the woods just to find interesting fungi instead of a meal, Climacodon is *far* more fun to find. It's very sappy and gooey when you break it and is unusual looking on its underside. Climacodon septentrionale teeth on the underside

Instead of gills or pores, the fruiting body produces teeth, or downward hanging spines, that bear the basidiospores. Teeth are another important way of increasing the surface area for bearing spores. See my Introduction to the Kingdom Fungi for more information on surface area and fruiting bodies. The surface area section starts here. Most fungi produce an enormous number of spores because of their specialized nutritional niche in the environment. The chance of any one spore landing on a substrate on which it can actually grow is very small. To compensate for this, most fungi produce enormous numbers of spores so that by chance a few of them will land on the proper substrate-- and the species will survive

Climacodon septentrionale is pronounced kli-MACK-uh-don sep-ten-tree-uh-NAIL-ee. Climac- means ladder and -odon means teeth, so literally the genus name means "ladder teeth." I'm not sure how this applies, but maybe it refers to always needing a ladder to cut this down from the tree, since it's usually found fruiting fairly high up. The rather romantic meaning of septentrionale is literally "from the direction of the north wind." So the common name of "northern tooth fungus" is a mostly literal translation of the Latin name (or vice versa).

So, you may be asking, why did I choose Climacodon septentrionale for the 50th Fungus of the Month? I had a very nice experience with this fungus, and I'll tell you the interesting saga. I received this email in November of 1999:

Dr. Volk,

Attached are two pictures of a large fungus brought in by some 
of my bio 1 students in ninth grade.  We were wondering if you 
could identify it for us.  We live in southern New Jersey.

Ray Jacobs, Biology Teacher, Memorial High School, Millville, NJ  

I happened to be sitting at my computer with a few minutes to spare, so I answered within a few minutes that I thought it was Climacodon septentrionale, the northern tooth fungus, and I told them a little about the fungus, as I've told you here. The students were apparently very grateful, and their teacher wrote emails of thanks. I answer emails like this all the time, so although it was fun, it was not an unusual occurrence. What happened after that was quite unusual though. I got an email from the Millville superintendent of schools thanking me for my response. The local Millville paper got wind of this and I spoke to a reporter about my website and the fungus. So that was all very nice.

New York Times ad Then some even more unusual things started to happen. I got emails, then phone calls, from BellAtlantic, the New England phone company. They had heard about my email exchange with the Millville students and had decided to do a major advertising campaign, touting what the internet could do for students in the schools. Then the phone calls and emails started coming. First I heard from the production company doing the print ad. They wondered did I have a specimen of Climacodon they could use for the ad? Well it was winter and there wasn't much to be found outside, so I searched my herbarium for a specimen and found one. I sent it by overnight mail to the people at the production company in New York City, who were taking pictures of the students and the fungus the next day. My fungus got a free trip to New York! Several days later, after the fungus returned, I got another phone call from the company doing the TV ad. ---could my fungus make a trip to Philadelphia? That month my fungus was traveling more than I was!

Finally in late May 2000, the full-page (!) ads began appearing, and I got a few copies, most notably from the New York Times, as shown to the left. New York Times ad closeup I allowed them to use one of my pictures of Climacodon also, center right, the same picture as the first one on this page. I still haven't figured out why they felt obligated to put the picture of the frog on the lower right in the ad. Maybe my fungus didn't seem charismatic enough. My name appears in the ad, as shown to the right in a blown up part of the ad, but they declined to list my website address, even though I requested it. Oh well, live and learn.

I never did get to see the TV commercial (we have a different phone company in Wisconsin), and no one has ever mentioned seeing it in New England, although I have many mycological friends on the east coast. Did anyone see it? I would love to have a copy someday.

So although I never expected to get anything in return when I answered the students from New Jersey, I got to experience all the excitement I've described here. Unfortunately, I don't have time to answer every single email I get, but I almost always answer email from students around the world.

Climacodon teethClimacodon septentrionale topI hope you enjoyed hearing the story of this month's fungus. I have enjoyed the surprises that were lurking behind a simple email. Lots of fun things can happen when you least expect it. That's why I like being a mycologist.

Thanks for reading the 50th Fungus of the Month. I never expected to get such a great response, and I hope to continue to publish a fungus of the month for as long as there are fungi to pick from. Actually I got an email a couple years ago from someone in France who had calculated how long it would be until I ran out of fungi, based just on the number of species I had pictures of online. I can't find the email any more, but it seems the date was sometime in the 2020's. There are LOTS of fungi, and each one has an interesting story.

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 2001 by Thomas J. Volk, University of Wisconsin-La Crosse.

Return to Tom Volk's Fungi Home Page --

Return to Tom Volk's Fungus of the month pages listing