Ustilaginoidea is a genus of fungi in the family Clavicipitaceae. The genus contains 19 species.[3] Ustilaginoidea was circumscribed by German botanist Julius Oscar Brefeld in 1895, with Ustilaginoidea oryzae assigned as the type species.[4] Ustilaginoidea virens causes the disesase known alternatively as rice false smut, pseudosmut, or green smut.