Fall is peak season for all kinds of mushrooms. You can see the greatest amount of mushrooms after a rainfall. Fungi produce spores instead of seeds for reproduction which are spread by the wind and by animals.
One of my favorite mushrooms is the giant puffball. It begins in the summer as a white, firm mushroom and by late fall it turns brown and is filled with trillions of spores. I like to find a good stick to whack them to watch the spores explode into clouds as dark as chocolate. Watching them explode is fun but NEVER TASTE a grown up puffball because they are POISONOUS.