Wood

Fungi are not plants.

Living things are organized for study into large, basic groups called kingdoms.
Fungi were listed in the Plant Kingdom for many years.
Then scientists learned that fungi show a closer relation to animals, but are unique and separate life forms.
Now, Fungi are placed in their own Kingdom.

It is a hidden kingdom. The part of the fungus that we see is only the “fruit” of the organism.
The living body of the fungus is a mycelium made out of a web of tiny filaments called hyphae. The mycelium is usually hidden in the soil, in wood, or another food source. A mycelium may fill a single ant, or cover many acres.
The branching hyphae can add over a half mile (1 km) of total length to the mycelium each day. These webs live unseen until they develop mushrooms, puffballs, truffles, brackets, cups, “birds nests,” “corals” or other fruiting bodies.
If the mycelium produces microscopic fruiting bodies, people may never notice the fungus.
(Wikipedea)

This coral fungi was quite spectacular on this old wooden tree stump..