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A Fan of Fungi: Green Elfcups

By James Reddoch

All the rain we have had this spring, summer, and fall has resulted in a spectacle for those interested in mushrooms. Even if you are not interested, you have probably seen them on your hikes, in your yard, and maybe even in places where you do not want them. I have turkey tail mushrooms sprouting from one of the logs in the back wall of my house – not good!

Mushrooms have the power to fascinate. For many, they are sought after for food or for medicinal purposes. For others, they are feared because of their potential to poison. I am not brave enough to determine which mushrooms are edible or helpful. I will leave that to professionals. But for me, they are an invitation into a part of our natural world that is often unseen and, in many instances, poorly understood.

As I have begun to explore mushrooms, a basic thing to understand is that the mushroom is the fruiting body of an often unseen fungus growing underground or within some other living or dead organic matter like a tree. By the way, what the mushroom is growing on is often a clue to its identification. For instance, some mushrooms only grow on certain species of trees. Can you guess where the Birch Polypore (Fomitopsis betulina) can be found?

So, when you see a mushroom, you are seeing the “fruit” of a fungi. Think of it this way: As apples are to an apple tree, mushrooms are to a fungus. The difference is when you pick an apple, you can see the entire tree from which it comes. When you pick a mushroom, unless you look closely, you don’t see the larger organism where it is growing.

Another thing to know about fungi and their fruiting bodies (mushrooms), is that they function in different ways within the forest. Some are saprophytic, which means they break down dead, organic matter, creating fertile soil in the process. In other cases, fungi form mycorrhizal networks with trees. This is a mutually beneficial relationship in which the fungi’s tendrils, known as mycelium, intertwine with a tree’s roots. This network allows the tree to better access water and certain nutrients like nitrogen. The fungi then receive a share of the sugars that the tree generates through photosynthesis. As many as 95 percent of the trees in our forests depend on this mycorrhizal relationship.

These are just a couple of ways that fungi function in our environment. But for me it is intriguing to remember that as I walk through the forest or in my yard, fungi are: busily recycling nutrients from organic matter, often sharing those nutrients with trees and other plants, creating rich soil, and storing massive amounts of carbon in the process. It has made me a fan of fungi!

One mushroom I ran across late this fall is commonly known as Green Elfcup. You have probably seen this fungus on a forest walk even if you didn’t know it. Look for a fallen log or decaying wood that is tinted green. The green color comes from a fungus known scientifically as Chlorociboria aeruginascens or its cousin Chloriciboria aeruginosa (less common). The two are indistinguishable to the naked eye so, for this article, I will use the common name Green Elfcup.

Although it can be commonly found in our forest, it is less common to see the fruiting body or mushroom. The mushrooms from this fungus are small ranging from less than one-tenth to two-tenths of an inch across. But when they erupt, they do so in dozens if not hundreds of stunning blue-green mushrooms. I was lucky enough to find several patches in my wanderings this fall.

Green Elfcup is classified as a saprophyte but experts say it may not decay the wood’s cell walls the way other “true” wood decaying fungi do. Scientists have investigated whether this fungus makes wood less appealing to other wood chewing insects like termites. They have also tested Green Elfcup as a possible algaecide and studied it for its potential cancer-fighting properties.

Green Elfcup is also used by wood carvers going as far back as the 14th century as a way of adding green color to their veneers. Click here to see examples.

Just as apple-picking season ends in the fall, the same is true for most mushrooms. But Green Elfcups can occur late into the fall. So until snow has buried them, watch for the fruiting bodies or the green-stained wood on your next walk. When you do, whisper a word of thanks for all the unseen fungi doing the work of building a healthy ecosystem.

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