Genus Ustilaginoidea is a group of fungi that includes species such as Ustilaginoidea virens, which causes smut disease in rice plants. Synonyms for this genus include Tolyposporium and Thecaphora. Formerly known as Ustilago virens, the species was reclassified into the Ustilaginoidea genus in 1944. Ustilaginoid fungi are mainly found on plants and are characterized by forming thick-walled spores and growing inside the host plant's tissues. The study of genus Ustilaginoidea is important for understanding the ecology of plant diseases and developing strategies to control them.