Iostephane is a genus of Mexican flowering plants in the sunflower family. The species are rosette-forming herbaceous perennials that produce relatively large heads with yellow or purple (I. heterophylla) rays. They have large, somewhat quadrate cypselae (achenes), that may either have or lack a pappus. Molecular phylogenetic studies suggested that there is an unexpectedly close relationship between Iostephane and Dendroviguiera (Viguiera sect. Maculatae), a genus of shrubs and trees that is also endemic to Mexico.