Bacteria Bacteria Bacteria (; common noun bacteria, singular bacterium) are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about half of the
Corticioid fungi and sedge stems, especially in marshes. Parasites of plants and other fungi are also found in the group. Corticioid fungi have a worldwide distribution, but are obviously commonest in forest communities. Corticioid fungi The corticioid fungi are a group of fungi in the Basidiomycota typically having effused, smooth basidiocarps (fruit bodies) that are formed on the undersides of dead tree trunks or branches. They are sometimes colloquially called crust fungi or patch fungi. Originally such fungi were referred to the genus "Corticium" ("corticioid" means "Corticium"-like) and subsequently to the family "Corticiaceae", but it is now known that all corticioid species