Species form thin, effused, corticioid basidiocarps (fruit bodies), but are most frequently found in their sterile, anamorphic state.

Rhizoctonia was introduced in 1815 by French mycologist Augustin Pyramus de Candolle for anamorphic plant pathogenic fungi that produce both hyphae and sclerotia.

[2] Subsequent authors added over 100 additional names to the genus, most of them plant pathogens bearing only a superficial resemblance to the type species.

This proposal was passed and the type of Rhizoctonia is now conserved as R. solani under the International Code of Nomenclature for algae, fungi, and plants.

[8] In 1971 Talbot & Keane introduced the genus Oncobasidium for a plant pathogenic species resembling Thanatephorus but lacking sclerotia[10] and in 1972 M.A.

[8] In 1978 Tu & Kimbrough introduced the genus Aquathanatephorus for an isolate from water hyacinth which produced a teleomorph with swollen, inwardly curving sterigmata.

These affinities were the possession of large sterigmata ("cerato-basidium" means "horned basidium") and the production of basidiospores that produce secondary spores.

[14] The genus Koleroga was proposed by Donk (1958) to accommodate K. noxia, a plant pathogen morphologically similar to Ceratobasidium but not known to produce secondary spores.

[4] Species are saprotrophic, often occurring in soil and producing basidiocarps (fruit bodies) on dead stems and plant detritus.