There are about 10,000 kinds of wild mushrooms in North America, and they have an astonishing array of shapes, sizes and colors. Mushrooms are neither plants nor animals. They constitute their own kingdom known as "Fungi". Fungi include all the familiar mushroom-forming species, as well as yeasts, molds, smuts and rusts. Mushrooms are a lot like plants, but unlike plants they don't have chlorophyll so they take nutrients from the materials they're in contact with.
You have to act fast if you want to enjoy eating wild mushrooms. Once they’ve shed their spores, most of them deteriorate pretty quickly.
We usually only see actual "fruit" of the Fungi kingdom(the mushrooms), because most of the action takes place underground or beneath the bark of dead or living trees. Before developing a mushroom, the fungus lives hidden as a mycelium. Mycelium is a mat-like network of white filaments that resembles a spider web, but it's made up of microscopic hyphae that grow gradually within a patch of soil or in wood. If you've ever kicked an old rotten stump and knocked off the bark, you might have seen mycelium. Many times the individual hyphae in a mycelium are no more than a 100th of a millimeter in diameter.
The hyphal growth begins from a single, minute mushroom spore (see diagram at right). Then a "germ tube" extends out from the spore, and additional "branches" grow forming a circular pattern.
Under the right conditions, mycelium develops a fruiting structure, a mushroom, which emerges from the ground or the tree. Instead of seeds, mushrooms produce tiny spores, which when released look much like smoke. When spores land in a suitable place, they germinate and the process begins again. Individual mycelium patches beneath the surface can grow to inhabit acres of land!
"Is this the largest organism in the world? This 2,400-acre (9.7 km2) site in eastern Oregon had a contiguous growth of mycelium before logging roads cut through it. Estimated at 1,665 football fields in size and 2,200 years old, this one fungus has killed the forest above it several times over, and in so doing has built deeper soil layers that allow the growth of ever-larger stands of trees. Mushroom-forming forest fungi are unique in that their mycelial mats can achieve such massive proportions."
~Paul Stamets, Mycelium Running
Types Of Mushrooms
Saprophytes or saprobic fungi are the housekeepers of the fungi kingdom. They digest nutrients from dead organic material, such as leaves on the forest floor and dead trees. Parasitic fungus are the vampires of the fungi kingdom. They digest materials from living tissues. If you see mushrooms growing on a live tree, the mycelium of those mushrooms have been at work inside the tree for a while. Parasitic fungi are rather creepy in that some invade insects and other living creatures too! Mycorrhizal fungi are a third group. They're friendly fungi. Underground, their mycelium mingle with other plant's roots, forming a mutually beneficial or symbiotic relationship with those plants. They help the plants to absorb water and minerals, and in return the plants provide nutrients to the fungus. Many trees and other plants cannot exist without these fungal partners.