These are known as club fungi and have a small base. These are the most common type of fungi. They have saprobic mode of nutrition. They can decompose cellulose and lignin so they are good decomposers of wood also. The hyphae are formed in the wood. No motile cells are present. Mycelia may be primary or secondary. Primary mycelia have mono karyotic cells. These multiply by formation of conidia and oidia. Secondary mycelium has di karyotic cells. These cells do not multiply by spore formation. No sex organs are involved in sexual reproduction. Plasmogamy occurs and is followed by karyogamy. The intermediate phase between two stages is known as dikaryophase. It gives rise to secondary mycelium. It has multiple septate hyphae. The septa have spores and hook shaped outgrowths. They are known as clamp connections. They penetrate by sclerotia or rhizomorphs. Septa mycelia multiply by formation of many spore including uredospore and chlamydospores. In basidia, karyogamy and meiosis occur which leads to the production of four meiospores. This fungus may form fruits known as basidiocarps. They may range from microscopic to macroscopic forms.