Mushrooms associated with trees, lawn, mulch, and even house plants, are macroscopic fruiting bodies of certain fungi. Fungi develop a microscopic network of structures underground (Hyphae, Mycelia), associated with trees and other plants, and often embedded in the substrate (soil, living or dead wood, etc.) and extracting nutrients from it. Mushrooms and fungi, in general, are one of the many nature's recyclers.
The networks of fungal mycelia develop in circles, and therefore in some instances, you can see mushrooms growing in large rings. For example, see Fairy Rings in Lawns.
Fungal fruiting bodies form when favorable environmental conditions, such as humidity and temperature, and spores develop within the mushroom.
Some mushrooms may be associated with living or declining trees and may have the appearance of brackets or conks. Some of them can cause wood decay, heartwood rots of trees, root and butt rot, in healthy or injured trees with cracks
Mushrooms may also develop in tree stumps. Once established in the lawn, tree, or tree stump, no cure or treatment is available. There is no treatment to eradicate them.
If you want to learn more about mushrooms common in IA, including a calendar of historical occurrence, role in nature, and known toxicity, see the field guide Safe Mushroom Foraging. For the interactive mushroom, calendar visit the Mushroom Foraging in Iowa page
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