Rotten Good

We like our tasty mushrooms, but fungi need to eat too. Their food source is usually dead or living plant material. Many of our choice edible mushrooms decay wood to get their nutrition. Some also have mycorrhizal relationships with specific plants, in which the plants benefit from getting nutrients from the fungus and the fungus benefits by getting sugars/food from the plant. I simplified the explanation, but this relationship is one form mutualism or symbiosis. Sometimes the relationship isn’t so mutually beneficial, and the fungus is damaging the living plant; a lot of plant pathogens (disease causing) are fungi.

This time of year, people are anticipating the upcoming hunt for the elusive morel. Morels aren’t really that mysterious, but they are often well hidden and quite variable. That is because there are several species and subspecies, and they will appear under different circumstances. Some are associated with specific trees (especially recently dead trees), some pop up abundantly after wildfires (especially in the Pacific Northwest), and some just seem to appear randomly. Around here, we commonly have the yellow morel (Morchella americana) and black morel (Morchella angusticeps), but it is more complicated when you start looking at subspecies and other nomenclature. Morels are notoriously difficult to cultivate, perhaps because they often grow in mycorrhizal association with host trees. The mycelium grows well in culture (without trees), but it is difficult to successfully stimulate the production of the much-loved mushroom itself. I’ve heard that some have solved that issue and can get morels to fruit in culture, but I’m going to stick to the fun of the hunt! I will be looking around the base of recently dead elm, ash, oak and apple trees, as the death of the mycorrhizal host plant can stimulate them to produce reproductive structures (e.g. morel mushrooms). Some of the other distinctive mycorrhizal fungi we collect to eat include chantarelles and boletes. As with morels, the key to finding these tasty mushrooms is understanding their ecology so that you know when and where to look.

Mushrooms that use decaying wood as a food source are a bit more predictable to collect. Many of them can even be cultivated in your own backyard. This year I am growing shiitake, native oyster mushrooms, and lions mane on logs; if you are just starting on mushroom growing, it is a big confidence booster to be able to watch the fruiting bodies develop and then harvest them under known conditions. (We still have some spots in the shiitake cultivation class on April 11^th.) One of my recent favorites to collect in the woods is the golden oyster mushroom, a non-native fungus that has unfortunately escaped from cultivation and spread aggressively throughout our woodlands. I usually find it on dead elm logs; they are so abundant that I have needed to come up with new ways to preserve them! My pantry is full of dried and pickled golden oyster mushrooms, and they have become a significant food source in our household. Other wood decay fungi that I harvest and use include chicken of the woods (Laitiporus sulphureous), native oysters (Pleurotus sp.), and resinous polypore (Ischnoderma resinosum). We’ll be talking about where to find these and others on our optional “habitat hike” after the shiitake cultivation class.

Sometimes fungi cross a line between being saprophytic (eating stuff that is already dead) and pathogenic (attacking living plant tissue to cause disease). For example, the Armillaria genus has multiple species with varying degrees of tree-killing ability. They are commonly implicated in the death of trees that are under stress due to drought, insect attack, or other things that weaken the tree’s defense response. Some people enjoy harvesting and eating the mushrooms of Armillaria,

but I haven’t tried them because I am extremely cautious about what mushrooms I eat, and there are some deadly mushrooms that look similar. Interestingly, there is another little mushroom in our woods that eats Armillaria! Entoloma abortivum parasitizes Armillaria and forms little aborted

mushrooms that look like white cheese curds on the forest floor. People call these structures “shrimp of the woods”, and they are quite tasty when fried up in butter! Many of our other pathogenic fungi that kill trees don’t produce edible mushrooms. Other tree diseases caused by fungi include Dutch elm disease, oak wilt, and a ton of various leafspot diseases.

We have some other favorite edible mushrooms that are not associated with decaying wood or dying trees. The mycelium of these fungi feed on decaying vegetation and plant material in the soil, and then their fruiting bodies pop up randomly or in fairy rings in the woods and lawns. An impressive one of these that we often find in the Fall is the giant puffball (Calventia gigantea). Another surprisingly tasty treat is the shaggy mane (Coprinus comatus), but you need to get them before they start to turn to a black slimy mass! (Sounds appealing, right?!)

I’m closing out this list of a few of my favorite rotten good fungi with the obligatory warnings. NEVER eat mushrooms if you are not absolutely certain that you know what you have collected; some mushrooms contain toxins that will make you very sick or kill you. Always cook your mushrooms well; even delicious, edible mushrooms (like morels!) can make you very sick if you don’t cook them thoroughly. Also be aware that compounds in some mushrooms interact with alcohol, causing severe sickness. And lastly, be aware that individual people may have a different reaction to mushrooms; for instance, some people can’t eat chicken of the woods or morels. So try any new wild food in limited quantities until you know how your individual body responds. Good ways to learn more about mushrooms are to hunt with a knowledgeable friend or take a class, or both!  Have fun-gi out there, but be careful!