When Eloise Butler started her wildflower garden, fungi were considered to be what I call pale plants because they were thought to be relatives of plants that lacked chlorophyll. In her garden log she frequently waxed poetical about interesting specimens, particularly edible ones: “Although not flowers, we cannot pass without a glance at the denizens of decaying logs and stumps. To students of fungi and epicures these forms of vegetation may be of more interest than the flowering plants. The … edible oyster mushroom, Pleurotus ostreatus, (photo below) is somewhat shell like in shape, and the individuals overlap one another like oysters attached to some substratum in the sea.”
Below: Minneapolis Park & Recreation Board Naturalist Diana Thottungal and her miniature mushroom zoo.
These days, fungi have a kingdom to themselves and, oddly enough, seem to be more closely related to animals than to plants. New research has messed up the Latin names of many fungi since DNA studies are coming up with surprising results showing species we regarded as closely related to be not only in different genera but even in different families. Now, an established common name is sometimes a better identifier for a mushroom than a new and unfamiliar Latin name. Furthermore, the new Latin names may differ from guidebook to guidebook. For example, the very common Turkey Tail can be found as either Coriolus, Polyporus, or Trametes versicolor, depending on when the book was written.
The Sulphur Shelf mushroom can cover an entire log with brilliant orange and yellow shelves. Photo by Judy Remington
So, what is a fungus? Besides being either very good to eat or deadly poisonous (depending on which one you pick), fungi include mushrooms, brackets, molds, rots, smuts, mildews, stinkhorns, yeasts and puffballs. What they have in common is that, instead of eating the way animals do, by taking food into their bodies, or manufacturing food like plants do, fungi basically live inside their food! Most of any fungus is a collection of long or short filaments called hyphae. These filaments exude juices that digest the surrounding stuff into chemical bits that are easily absorbed into the fungal cells. Also unlike plants, which have cell walls of cellulose, fungi have cell walls of chitin, like insects do.
Fungi grow inside dead plants, wrapped around living roots, inside an animal’s gut or skin: places that are a good source of food. A few act as parasites on live plants or animals. And some fungi set up housekeeping with an alga; the result is called a lichen, which lives and reproduces as one organism, not two.
Mycorrhizal mushrooms (the name translates to fungi of roots) are critical to helping trees get nutrients efficiently from the soil, and most trees would remain rather tiny year after year without their fungal helpers. A famous mycorrhizal mushroom is the honey mushroom, Armillarea mellea. A specimen of this growing in Oregon has the distinction of being the largest living organism known in the world and covers 2,200 acres of forest. Three feet thick and three-and-a-half miles across, this specimen is thought to be 2,400 years old.
Some fungi break down forest leaf litter and can be very picky about which species they work on. For instance, some only grow on oak leaves, others only on pine cones.
Mushrooms fruit when they feel like it. Not only do the season, nutrients and environment have to be right, there also needs to be the right amount of rain. Because many of them are living inside logs or underground, waiting for the right moment, it’s a bit hard to predict when they’ll show up, although, like perennial plants, many appear in the same location, sometimes for decades. One spot in the Garden, along the east woodland trail, was named “Puffball Flats” by Eloise and to this day reliably produces puffballs. Approximately 250 mushroom species have been identified in and right around the Garden, and about 50 more are awaiting names.
Recently, to get around this idiosyncratic behavior, we have established a mushroom zoo behind the shelter, which we water when the weather won’t cooperate. It houses about 30 species, which helps to make mushroom walks a bit more productive.
Strangling worms. Several kinds of fungus, when hungry, catch (and eat) tiny nematode worms in a three-cell noose that closes in a tenth of a second when the unwary creature attempts to pass by.
This one’s for the birds. A bracket fungus called Spongipellus pachyodon softens the heartwood of many trees. Then woodpeckers like our hairy, downy and pileated have an easier time pecking out nest holes. Apparently, the woodpeckers sound out the softened areas by hearing the differences when drumming on the trunk.
Christmas trees would have a hard time growing without the fungi that help the roots absorb nutrients. Without them, the trees would only grow about three feet in 10 years.
Stonewashed jeans aren’t washed with stones; they’re soaked in a vat with a fungus that breaks down the cotton cellulose to makes the jeans soft.
Eating CDs. There’s now a fungus that can live off of, and destroy, your CDs. It was found in 2001 in Belize when a CD was found to have lost its information. The fungus had bored in from the edge and nibbled the tasty bytes and bits inside.
Vanilla Orchids. The orchid that produces vanilla flavoring (and many other orchids, too) could not even start growing without its friendly fungus.
Below: The Oyster Mushroom (Pleurotusw ostreatus). Photo by Diana Thottungal.
Diana Thottungal has worked as a volunteer and a naturalist at the Garden for more than 10 years and became interested in fungi one very rainy June a few years ago.
Note: This article was published in the Fringed Gentian™, Autumn 2008-2010, Vol. 56, #4.