Winter is a great time to look at certain elements that are more difficult to see in the forest when all of the trees have their leaves. One of those might be fan-shaped or shelf-like growths that on the sides of trees and stumps.
These growths are actually a type of fungus called shelf or bracket fungi. Bracket fungi are related to puffballs and mushrooms, as well as other fungi. Many are woody and long-lasting in nature, while a few are fleshy and short-lived. These fungi are non-photosynthetic, which means they are unable to produce their own food by using the sun’s energy. Instead, these organisms get their nutrition by digesting cellulose and lignin within the wood on which they are growing. They are an important part of the nutrient cycle in a healthy forest.
All bracket fungi used to be classified as part of the same group; however, physical differences and recent DNA studies have helped to differentiate them into several taxonomic groups.
A bracket fungus begins its life as a spore, one of hundreds of thousands produced by a mature fungus. If the spore lands on a favorable location, such as a tree stump, it sprouts tiny thread-like mycelium, which invade the stump. Mycelium cells manufacture and secrete enzymes that digest the wood. The tree’s cellulose is broken down into its simple sugar building blocks, which are absorbed by the fungus. The space vacated by the dissolved wood leaves room for the fungal mycelium to grow deeper into the tree.
Just like humans, shelf fungi need more than sugar to grow and be healthy. Aside from sugar, shelf fungi also require vitamins and minerals, such as sulfur, potassium and magnesium — all of which are obtained from their host log, stump or tree. They also need a suitable temperature and pH level, as well as adequate water.
When environmental and nutritional conditions are favorable, the fungi grows its characteristic shelf on the outside of the stump. This recognizable part, the fruiting body or basidiocarp, produces more spores and the cycle begins again.
Most shelf fungi digest dead wood, but others attack living trees, eventually causing their death. Many kinds of bracket fungi only grow on specific kinds of wood, such as beech, cherry, hemlock, birch or oak. It is believed that nutritional requirements and/or an inability to digest certain woods limit where each can grow.
Most bracket fungi that are visible during the winter are woody and perennial, adding a new layer to their shelves each year — thus getting larger and thicker. The largest and best-known of the Pennsylvania species is the artist’s fungus, which can grow to 24 inches across and weigh 20 pounds. The fungi’s clean white underside can be used as a unique drawing, painting or carving medium.
The hemlock varnish shelf, as its name would indicate, usually grows on our state tree — the hemlock. A similar woody species, lacquered polypore, grows on hardwoods.
One of my favorites is cinnabar polypore, which I learned as “cinnabarinus” — its species name. (The name cinnabarinus just rolls off my tongue nicely.) This bracket fungus is bright orange and easily spotted. I usually find it growing on cherry logs, such as a group I photographed on State Game Land 278 just south of Centre County.
Other shelf fungi are fleshy and short-lived; some can even be eaten. Edible fungi with shelf-like growths include oyster mushrooms, hen-of-the-woods, chicken-of-the-woods (also called the sulphur shelf) and beefsteak fungi.
Chicken-of-the-woods is yellow and orange and grows on dead trees and stumps. I have collected and eaten it on several occasions, and it is common in our area. It has the texture of chicken breast but the flavor of a mushroom. This shelf fungus can be found from late summer through early fall. It is best collected when it is still plump and fleshy.
In his excellent “Field Guide to Wild Mushrooms,” local author Bill Russell writes, “This is a very easy mushroom to identify and is not easily confused with other species. Remember where you find chicken mushrooms growing, because they can reappear every year, sometimes for several years.” Also remember to heed the old mushroom collector’s advice — never eat an unfamiliar fungus without first having it identified by someone who has eaten it and lived.
