Slime mold or slime mould is an informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies which may be formed through aggregation or fusion. Slime molds were formerly classified as fungi but are no longer considered part of that kingdom. Although not forming a single monophyletic clade, they are grouped within the paraphyletic group Protista. More than 900 species of slime mold occur globally. Their common name refers to part of some of these organisms' life cycles where they can appear as gelatinous "slime". This is mostly seen with the Myxogastria, which are the only macroscopic slime molds. Most slime molds are smaller than a few centimetres, but some species may reach sizes up to several square metres and masses up to 20 kilograms. They feed on microorganisms that live in any type of dead plant material. They contribute to the decomposition of dead vegetation, and feed on bacteria and fungi. For this reason, slime molds are usually found in soil, lawns, and on the forest floor, commonly on deciduous logs. In tropical areas they are also common on inflorescences and fruits, and in aerial situations (e.g., in the canopy of trees). In urban areas, they are found on mulch or in the leaf mold in rain gutters, and also grow in air conditioners, especially when the drain is blocked. Taxonomy Older classification Slime molds, as a group, are polyphyletic. They were originally represented by the subkingdom Gymnomycota in the Fungi kingdom and included the defunct phyla Myxomycota, Acrasiomycota, and Labyrinthulomycota. Slime molds are now divided among several supergroups, none of which is included in the kingdom Fungi. Slime molds can generally be divided into two main groups. A plasmodial slime mold is enclosed within a single membrane without walls and is one large cell. This "supercell" (a syncytium) is essentially a bag of cytoplasm containing thousands of individual nuclei. See heterokaryosis. By contrast, cellular slime molds spend most of their lives as individual unicellular protists, but when a chemical signal is secreted, they assemble into a cluster that acts as one organism. Modern classification In more strict terms, slime molds comprise the mycetozoan group of the amoebozoa. Mycetozoa include the following three groups: Myxogastria or myxomycetes: syncytial, plasmodial, or acellular slime molds