There's an old saying among botanists: If you take a walk in the woods with a botanist, you'll never get where you're going.
Botanists, you see, like to stop and look at every plant along the way.
The same could be said for a walk with a mushroom expert. They look under what seems like every fallen leaf, inspect every downed mossy log, stare into any hollowed trunk of any standing tree and constantly gaze toward the tree canopy. They know these are the most likely places to find mushrooms. Which is to say a mushroom expert can find a mushroom almost anywhere in a hardwood forest. (There is one notable difference between a walk with a botanist and one with the mushroom expert: The mushroom expert can teach survival skills that will come in handy if you ever find yourself lost in the woods.)
Tradd Cotter is a mushroom expert. Cotter is a mycologist — a person who studies mushrooms and other fungi — who, with his wife Olga, owns and operates Mushroom Mountain, an ecotourism farm in Easley, South Carolina. It's become a destination for people interested in exploring or studying the world of mushrooms. The farm features a 50,000-square-foot world-class laboratory and research facility that meets EPA and FDA standards and houses more than 200 species of fungi.
Perhaps the farm's most appealing attraction, though, is a mushroom trail that the Cotters consider the best of its kind.
"We collect and clone species indigenous to the region and respawn them along the trail at designated areas," Cotter said. "It's like a living mushroom zoo that helps us learn a lot about how these mushrooms can be cultivated as well as to compare the different species in the same genera."
For Cotter, any trail in the woods is a mushroom trail. That's the first thing I learned on a mushroom walk that Cotter led during a Native Plant Conference hosted annually by Western Carolina University in Cullowhee, North Carolina. Here are some of the many things I learned about mushrooms on that walk, which took us on a winding, up-and-down trail at the Standing Rock Overlook on the Blue Ridge Parkway (elevation 3,915 feet) just a few miles from the Western Carolina campus.
Most wild mushrooms are safe to eat. The No. 1 question on the walk: What wild mushrooms are edible? "All of them," Cotter deadpanned, going into a prolonged pause before adding, "for 30 minutes." Turning serious, he said, "There's not many poisonous or deadly mushrooms in the woods by comparison. The overwhelming majority are safe to eat, although as a previous MNN story points out, some wild mushrooms are edible and some are not — and it helps to know the difference. If you were stranded, mushrooms picked with care may be a good option for a food source. There's far more poisonous plants in the woods than there are poisonous mushrooms. But that's only an option in the spring and summer. If you become lost in the fall or winter, you are going to have to look for something else to eat."
Never guess which mushrooms are edible and which aren't. While most wild mushrooms are edible, some of the safe ones have a bitter or otherwise unpleasant taste and should be avoided. Poisonous mushrooms can have consequences ranging from making you painfully sick with gastrointestinal distress to destroying the liver or other internal organs and causing death. "Never guess!" Cotter stressed. If you find a mushroom that something has bitten into, don't assume it's safe to eat. "What a squirrel or other wild animal can eat and what a human can eat are not always the same thing," Cotter said.
There's no easy way to tell the difference between an edible and a non-edible mushroom. Experts like Cotter have learned the difference through years of study and field experience. They look at the underside of a mushroom's cap to see whether it has pores or gills, or its spore print or its stem to see if it has a collar. Unless you've taken a class in food safety that focuses on mushrooms and trust your learning, a good rule of thumb is to have an expert look at any mushroom you've picked in the wild before eating it. "Joining a local mushroom club is a great way to hunt and identify mushrooms with people who have experience," Cotter said. "Namyco.org [North American Mycological Association] is a good website that lists clubs closest to you in the United States." He emphasizes that people shouldn't "trust online forums and images for identification."
Some basic rules about edibility. There are some basic rules to determine whether a terrestrial pored mushroom with stems in the group commonly called "boletes" is edible. Cotter spells out the rules below, but as one keen reader points out, these are specific to this area of the country. Cotter is talking about mushrooms in the Southern Appalachians. Check with mushroom experts in your region of the country to see if these rules apply where you live.
- Determine the color of the pores. If they are red or orange, it is poisonous to humans. If they are pink, they are edible but too bitter to be enjoyable. If they are yellow, it is edible and go to Step Two.
- Does it bruise blue? Cut into the cap with a knife to bruise the mushroom. If it bruises blue, it could be poisonous. If it does not turn blue, go to Step Three.
- The question now is, does it taste good? To find out, chew on a very small piece of cap tissue for 30 seconds and spit it out if bitter or disagreeable. If mild, nutty or buttery, it’s a good species to eat. This quick and simple taste test will avoid the possibility of cooking up a batch of Bolete mushrooms only to discover they have a bitter taste.
Some mushrooms to avoid. White stemmed mushrooms with red tops are high on this list. They are in a group called the sickeners. Russula emetica, for example, has earned the common name "vomiting russula."
All mushrooms are safe to handle. Any mushroom, poisonous or not, can be picked and handled, Cotter said. "You can only become sick — or worse — by ingesting a mushroom," he explained. "You literally have to chew up a poisonous mushroom and keep it down for it to harm you."
Never pull a mushroom straight out of the ground. Chances are you will break the stem off the base, and you need the base to correctly identify it. "The bulbous base is what you want to protect," Cotter said. "Some are very fragile." A white mushroom with patches on top, for example, can have very deep stems. "All of the Amanita mushrooms are classified by a bulb on the base of the stem, which can be like a collar," Cotter said. "The only way to identify this type of mushroom is to dig down deep enough to pull up the base of the mushroom." Amanitas that are all white are some of the deadliest mushrooms, he added.
Raw mushrooms are not digestible. That's because mushrooms are made of chitin, Cotter said. Chitin forms the cell walls of fungi and arthropods, including all crustaceans and insects. Humans don't have chitinase in their gut bacteria, he added, which is needed to break down the chitin and make nutrients available. "So, if you are out in the woods and you're stranded and you're eating mushrooms, they might fill you up but they won’t give you a lot of energy," Cotter said. "If you cook them, it makes them bioavailable." That's because chitin is like a heat-unstable chemical lock that loosens into digestible sugars when cooked lightly, Cotter explained. "Next time you are at a salad bar, this is something to remember," he said. Or the produce section of the grocery store, for that matter.
Be aware of lookalikes. To the inexperienced eye, some toxic mushrooms can resemble edible mushrooms. It's important to know how to tell the difference. As an example, Cotter held up a chanterelle mushroom that we found. Chanterelles are edible, come in a variety of colors including pink, orange and yellow, have forking webbed gills and when you cut them open they will have flesh that is whiter than the exterior, he explained. Orange or yellow chanterelles can become very large, and can resemble jack-o'-lantern mushrooms, which are toxic, he added. A way to tell the difference between jack-o-lanterns and chanterelles is that the gills in jack-o'-lantern don't fork, are deep and when you cut them open the flesh color inside is a distinct orange.
If you see a squirrel digging, look for truffles. Small holes in the ground that look like they were made by an animal such as a squirrel may be a sign that truffles are in the area. Truffles in the mountains grow on oak trees. They are called pecan truffles because they were first seen growing on pecan trees. But they also grow on oaks. Truffles are edible and considered a delicacy.
Mushrooms grow almost anywhere. That includes the forest floor under or through the leaf litter; on banks of a slope, especially where two slopes come together and form a wash; fallen logs, particularly mossy logs; inside the hollows of standing trees; and along the trunks of trees, both near the ground and high on the trunks as they stretch toward the canopy. "There are 4,000 to 5,000 species of mushrooms in the Appalachian Mountains," Cotter said. "In the southern range of the mountains there might be 1,800 different species in any given summer. There are an estimated 5 million fungi on the planet, and new species are being discovered and named every day."
Here's a video showing Cotter collecting a highly desirable "lion's mane" mushroom. The tree is covered with poison ivy, just one of the reasons Cotter said this is something he doesn't encourage a person inexperienced in mushroom collecting to do, especially if they are alone in the woods. The video was not shot on the Cullowhee Native Plant Conference field trip.
Beware of big mushrooms growing at the base of a tree. "It's highly likely that these mushrooms are growing from a center rot or a bud rot," Cotter said. "These rots weaken the tree, and then it falls." If this happens in the woods, it would only raise the proverbial question of whether a tree falling in the forest makes any sound as it crashes to the ground. If it's a condition that you discover in your home landscape, it’s an entirely different matter. Then it's time to call an arborist to get a professional opinion on whether the tree should be removed.
There's a mushroom that glows in the dark. One mushroom we collected, Panellus stipticus, falls into this group. It has gills that are bioluminescent and glow a faint green in the dark.
There's also one that can carry fire. Fomes fomentarius will fold up into a sort of insulated pouch that can hold campfire embers. You can carry the embers to the next campsite to start a new fire.
There's a fungus that makes music. Cotter told a fascinating story about a black fungus we found, Xylaria polymorpha, or "dead man's fingers," as it's commonly known. "Everybody knows what a Stradivarius is, right?" he asked, referring to the famous violins made by the Stradivari family during the 17th and 18th centuries. "There's no wood left to make any Stradavaria anymore. Some researchers in Holland researched how to take black threads from this Xyalaria," he said, holding up the fungus. "They cultured it just like I culture mushrooms in my lab and they inoculated the mycelium and spread it on the wood plates that they carve the violins out of. Then they let the fungus grow in the wood and hollow out the wood tubes. After that they carved the violin. It had the same resonance if not better than a new violin and even out-competed a 200-to-300-year-old Stradivarius in a sound competition."
There's a mushroom that Cotter is making into flip flops. Cotter handed members of our group a mushroom (Daedaleopsis) he found and asked them to bend and twist it. "Notice how pliable it is?" he asked. "I'm making fungal flops out of them," he said as the group broke into laughter. "Hey," he said, "if you're walking in the forest and can't find anything to eat, you could cook your shoes!" Cotter couldn't say which species he is using for this project for proprietary reasons, but did say that rubbery polypores are being experimented with, they are edible and they also have antibiotic properties — which means they don't smell.
Mushrooms have helped build topsoil through the eons. Mushrooms and other fungus are decomposers that create soil. "In upstate South Carolina [the mountains], the topsoil in the early 1900s was 12 to 15 feet deep," Cotter said. "Now it’s 5 to 8 inches deep. It takes mushrooms in a healthy ecosystem such as the Appalachian Mountains anywhere from 500 to 800 years to make an inch of soil. So, if we had the ability to add that 12 feet of topsoil back, it would take 79,000 years to restore the topsoil to where it was in these mountains just a little more than 100 years ago," Cotter added. That's something to think about when you rake leaves in the fall, bag them and put them on the curb.
Don't get too hung up on scientific names. Mushroom experts use scientific names, but it's probably not necessary for the novice to commit all of them to memory. There are, however, a few names you may want to remember — including Boletus or Boletales, which are among the most common mushrooms you're likely to find on almost any walk; Amanitas, a large genus that includes some of the world's most toxic mushrooms and another good candidate for a genus you're apt to find on a walk in the woods; and Cordyceps, a fungus growing from a beetle or other insect and an indication truffles may be present. (We found one of these, and it piqued Cotter's scientific interests as much as any mushroom we found. "This is like the holy grail out here," he said.)
What to bring on a mushroom walk
- A basket to carry specimens you'll collect and identify (also called 'key out') at the end of the walk
- A little plastic box with compartments like the ones that hold fishing lures to prevent small specimens from being crushed
- Several field guides because the guides don't tend to be comprehensive. Because mushrooms vary from place to place, find a guide specific to your region. In the Southeastern United States, Cotter uses "Mushrooms of the Southeastern United States" and "Mushrooms of West Virginia and Central Appalachians."
- A hand lens to look at gills, pores and stems to help in identification
- Bug spray
- A backpack to help keep your hands free
- Rain gear
- A pocket knife to dig up mushrooms
- A walking stick for steep terrain (which can also serve as a pointer when you spot something difficult to see, such as morels)
Finally, it helps to be in reasonably good physical condition. Walks can be long — 3 to 5 miles sometimes — and can become strenuous, especially in the mountains where there are elevation changes.
One saving grace: Mushroom experts like to stop and look a lot.