Tree fungus can be a problem for arborists and landscapers, as they can cause decay and discoloration of wood. The fungi are usually able to enter through wounds such as pruning, wind damage, lawn mower injury, excavation for buildings, curbs or sidewalks, and trenching for water and gas lines.
There are many types of fungi that can infect trees. Some are harmless and others can be very damaging to the tree.
Shelf Fungus
A shelf fungus is a woody or leathery fungus that grows on or under the bark of living trees. These fungi are a special type of tree fungus that provides habitat for many animals.
They grow in a variety of tree species including alder, ash, beech, birch, catalpa, cherry, chestnut, citrus, elm, fern, fir, gingko, hackberry, holly, juniper, laurel, maple, oak, pine, redbud, spruce, sweet gum, tulip tree and willow.
These fungi cause white rot, which can lead to death of the host. Decay begins in the bark and progresses to the roots, trunk and branches.
They are usually found on dead or dying trees but can also occur on living ones, especially during environmental stress such as drought. Their fruiting bodies are thin, leathery and bracket-like with no stalks. They can be up to 1 inch across.
Artist’s Conk Fungus
The Artist’s Conk Fungus, Ganoderma applanatum, is a widespread and common species of tree fungus found throughout North America. It is a parasitic tree fungus that grows on living trees and decaying wood. It’s saprophytic, which means that it breaks down organic matter, and returns nutrients to the soil.
It produces spores in the form of elliptical brown to reddish-brown, sometimes black, capsules that are easily seen under a microscope. These caps contain two walls and dark columns that make up the spores.
This fungus is an important part of forest ecosystems, breaking down dead or dying tree wood and returning nutrients back to the soil. It is a common problem in older beech or poplar trees, but can also attack spruce, maples, and oaks.
Fly Amanita Mushrooms
Fly agaric, or Amanita muscaria, is a poisonous mushroom in the family Amanitaceae (order Agaricales). It grows under a variety of trees, including pine, birch and oak, and has been invasive to New Zealand, Australia and South Africa.
This large iconic mushroom is generally bright red to orange with white “warts” and a white underside. It has a ring on the stem slightly below the cap, a veil (volva) that is torn as the cap expands and a cup from which the stalk arises.
When this type of tree fungus is young, its body is entirely enclosed by a white universal veil. This gives the fruiting body an egg-like appearance. As the fruiting body grows, the veil breaks apart, leaving a volva at the base of the stem and little white warts or speckles on the cap. These white spots are one of the most recognizable features of this species. They’re also often used in picture-book illustrations. In fact, this fungus is so recognizable that Father Christmas is often shown with a red-and-white cap.
Pine Cone Fungus
Pine Cone Fungus (Auriscalpium vulgare) looks pretty strange, growing almost always from rotting pine and spruce cones. It is found in most of Europe, Asia and the Americas.
This tree fungus grows on the edges of cones, with fine bristles covering its cap, giving it a felty brown appearance. Its fruitbody is small, but tough and dark brown with age.
As a saprotroph, it decomposes dead organic matter. It does this to enhance its fitness, by reducing competition and increasing resources for reproductive activities. In addition, it is capable of generating a resistant spore bank and of establishing positive biotic interactions with mammals. It also has long-distance dispersal capacity, making it suitable for colonization of previously uninvaded ecosystems. These traits can explain its role in pine invasions.