What you see growing are the stalks(mushrooms) of Mycorrhizal Fungi. They generally are in a symbiotic relationship with plants where water and nutrients are shared. This is important because they enhance the roots of growing plants by making connections that are not damaging. They can be thought of as extensions of roots as well as lifelines of nutrients & water in the soil back to plants. The relationship of Mycorrhizal Fungi is also important because it is a critical organism for reducing a number of stress conditions that may exist or develop in the soil.