Mushroom Recipes Contact the Council Site Index Excerpted from . . . To understand spawn, spawning and spawn growth, the mushroom itself must be understood. Mushrooms are fruits of the fungus plant and consist of two main parts, the cap and the stem. As the mushroom matures the cap opens and the gills are exposed. Mushroom spores are produced in the gills.
Spores are microscopic spheres roughly comparable with the seeds of higher plants.
These spores are produced in large numbers in the gills. Since spores germinate and grows into mycelium rather than unpredictably, they are not used to seed mushroom compost. Spores will germinate and grow into a thread-like mycelium, which a laboratory producing spawn uses. Mycelium from the spores is placed onto steam-sterilized grain fully grown through by the mycelium is spawn, and spawn is used to seed mushroom compost. Spawn was first obtained by digging up wild mycelium from meadows where wild agarics grew and horses were active.