Shelf or bracket fungi tend to grow in somewhat circular shapes. They can be parasitic, saprotrophic (decomposing) or both. Many times these fungi can kill the tree they infest and then continue to live on it for years after its death. Some species have multi-colored growth rings just like the trees they eat.
A few of these are edible! Pleurotus ostreatus (oyster mushroom) is commonly cultivated for food. Polyporus squamosus, or Dryad’s Saddle is listed by many sites as an edible. Be sure you learn your Shroom ID before gnawing on one of these.
Sadly, once a tree is infected, the fungus cannot be killed. These fungi cause either white or brown rot in the heartwood; both are structurally weakening. The brown rots are the result of a fungus not being able to break down lignin in the cell walls (Lignin is what makes cells strong). White rots attack both lignin and cellulose. Sometimes, the tree becomes hollow, yet remains stable, however decay usually leads to weakening of the trunk, eventual limb fractures or toppling. Top rots which affect upper parts of the tree are less hazardous (dropped branches) than the root or butt rots which can be quite damaging because the whole tree may fall!
Bracket fungi cause millions of dollars in damage through lost wood production in the lumber trade. The only mitigation is to harvest the tree before the rot spreads too far. Income is lost because foresters need to harvest more wood to make quotas. Removing the infected trees decreases nesting sites for birds and animals, also. The rotten wood is easier to excavate and fallen logs provide cover.
There is a good side to these fungi!
The Chinese and Japanese continue to use many types of bracket fungi as a way to prevent and treat a number of diseases, including hepatitis, hypertension, bronchial asthma, chronic bronchitis, rheumatism, cancer, reduce saracoma 180 (cancer in connective tissues), esophageal carcinoma (malignant tumor with epithelial cells), hyperglycemia and to treat rheumatic tuberculosis. They have also been used to relieve pain, reducing fever, indigestion and hemostasis, and reducing levels of phlegm, steroids, fatty acids, applanoxidic acid, ganoderic acid, ganoderenic acid, and furanoganoderic acid. Studies have been conducted which show the fungi has antitumor, antimicrobial, antibronchial asthma, immune-stimulating, immune-regulating, liver- protecting, anti-hypertensive, anti-hyperglycemic, anti-allergic and anti-oxidative properties. Antibacterial properties are also found in the tube layers of Artist conk (Ganoderma applanatum). It prevents tumor growth and increases white blood cell activity. Extracts from Ganoderma applanatum lower glucose, cholesterol, and triglyceride levels significantly.
I brought up Artist Conk, want to know why it is called that? When the bottom is touched, it bruises the tender white underbelly a dark brown. Many folks have some beautiful art with Artist Conk as their medium.
Remember, mycelium, the body of the fungus, decomposes chemicals in the tree cells. White rots attack both lignin and cellulose, which are the molecules found in paper. The rotted wood is white because that is the color of the cellulose left behind. Scientists are experimenting using white rot fungi to convert wood chips to paper pulp. This process reduces energy use and pollutants. White rot fungi can also destroy toxic chemicals like PCB’s in soil. Go Go Fungi power!
Fungi are just the suckerfish of the woodlands. Someone has to do the dirty, clean-up work so the cycle of life can go on in the forest.
© Ilex – Midwestern Plant Girl