Fungi
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds as well as the more familiar mushrooms. These organism is classified in the kingdom, Fungi, which is separated from the plants, animal and bacteria. One major difference is that the fungus have cell walls. These and other differences show that the fungi form a single group of related organisms, named the Eumycota.
http://en.wikipedia.org/wiki/Fungus
http://en.wikipedia.org/wiki/Fungus