The loners of the fungus world feed on dead or dying plants
and animalseven dung. These are the rotters and decayers
that most people think of when you mention fungi. They break
down dead tissues and then absorb the digested material. This
is known as a saprobic
lifestyle, and these fungi are called saprobes.
Many of the fleshy fungi are saprobes. Often they appear to
be growing in the soil, but if you scrape away the surface you'll
find their true substrate, a rotting log or perhaps an earthworm
or insect carcass.
Commonly the underground part of the fungus, a network or mycelium
of thin filaments called hyphae,
grows outward from this substrate in all directions at the same
rate. Eventually, mushrooms appearas if by magicin
a circle aptly named a fairy ring.