Fungi in the forest F. Nishida
Mushrooms aren't really plants, they are types of fungi that have a "plantlike" form - with a stem and cap (they have cell walls as well). This is really just the "flower or fruit" of the mushroom - the reproductive part which disperses the spores. The larger portion of many fungi is underground, and can be acres in size! Mushrooms aren't plants because they don't make their own food (plants use photosynthesis to make food). The underground part of the fungus uses enzymes to "digest" other substances that it can use as food. Mushrooms and other fungi often grow in association with plants - perhaps attaching to the side of a tree, or growing out of a dead log as it decays. They are important in helping to "recycle" nutrients and break down dead plant materials.
Some fungi are very colorful - often with orange or red coloration. Others are less noticeable, blending into the litter on the forest floor. Depending on what time of year it is, you may see the "flowering" part of the mushroom, as the fungus enters it's reproductive phase. Many mushrooms are poisonous, so they should not be touched, as even a small amount of spores can have an effect on humans. Mushrooms generally aren't eaten by other animals, since they are mostly water and have little nutritional value as well as being toxic. Most of the mushrooms that humans eat are cultivated rather than wild.