Friday, September 25, 2009

Fungus Hike

Posted by Kirk
I had the pleasure this week to go on a fungus hike at work with a former president of the Minnesota Mycological Society.

Fungi are not my strong suit as a naturalist so it was fascinating to go on a hike with her and learn more. Here's some of what we came across on our short hike.

First up is Ischnoderma resinosum. If you're not familiar with fungi I should point out here that many of them don't have common names. This is a polypore mushroom that grows on the sides of fallen dead trees in the woods. It is a saprobe meaning it feeds off of and helps decompose dead wood.

If you're not at all familiar with mushrooms, what you are looking at above is considered the fruiting body of the fungus. Most of the fungus is actually inside the wood of the tree. When the fungus is ready to reproduce it creates the "mushroom" we're familiar with who's purpose is to create and spread spores.
Here's a view of Ischnoderma resinosum growing on the same log but in a grouping.

Here's one with a human hand for size reference.

Just above this grouping was something strange on the log. Take a look at the photo below.

According to our guide, this is also Ischnoderma resinosum. Size wise the sticky clump on this fungus is about the size of a quarter. In order to release the spores from the mushroom they must be very dry. According to our guide the mushroom excretes resin as a way to get rid of excess water. I hope I understood that correctly.

Up next was slime mold. Slime molds are one of the most fascinating things in the woods and I really need to take some time to learn more about them. They are not molds as their name suggests. They are not even fungi. Mycologists study them out of tradition but technically they are in their own special group distinct from fungi. Much of the time, slime molds are plasmodium. A plasmodia is a mass of protoplasm without a cell wall. It is sort of amoeba like in this sense. Slime mold plasmodia can actually move! They slowly move over the surface of a given material such as a log and surround bacteria, protozoa, etc. and using them as a nutrient source. eventually, the plasmodia undergo a change and turn into a structure to produce spores. Unlike fungi which penetrate trees and then just produce a fruiting body on the surface, slime molds spend their entire time at the surface. What you see is what you get. What you get can very wildly in appearance though.

Check out this cool photo. That's a red oak leaf in the foreground for some size reference. These were very small. These are the spore producing sporangia (spore cases) of the slime mold Stemonitis sp. It is sometimes called chocolate tube slime.

Here's another slime mold in spore bearing mode. This is the insect-egg slime mold. If you click to view the full size image you can see that they are not perfect spheres. They have a little elongated section where they attach to the tree.

Venturing deeper into the forest we came upon this vey large specimin of Hypsizygus ulmarius growing on a box elder. This is a really fun fungus as it smells like a really nice perfume. It is subtle but nice. Who would have thought?

Up next was Turkey Tail. A common fungus I thought I knew. I turns out though that there is also a false Turkey Tail. The one pictured below is a true turkey tail. The true form is a polypore fungus. On the underside are thousands of little pores all packed together. If you have good eyes you can see them with your naked eyes but a 10x loupe does wonders. The underside of false Turkey Tail, by contrast, is smooth.

Toward the end of our hike we passed an area with a lot of oak bark woodchips. This is the site where we set up a portable sawmill to deal with all the downed trees after a tornado swept though the nature center last year. The ground is covered with decomposing bark and it was a great place to look for fungus. We couldn't help but notice this huge fawn mushroom. You can see why it is considered a "gilled" mushroom. The top of these mushrooms are fawn colored which gives them their common name.

My camera ran out of batteries so there were many fungi we found that I was not able to photograph. I did get a photo of one more though. It was actually growing at the base of the large red oak in the background of the above picture. The fungus below is one of three Peziza sp. that I found. It is a cup fungus.

That's all for the fungus. Stop back in the next few days. I have a couple of photos of something else fun I found on the hike.



Lynne at Hasty Brook said...

I've found the chocolate tube slime mold in our woods but have never seen an insect-egg slime mold! Very neat.