Geniostoma is a genus of around 25 species of flowering plants in the family Loganiaceae. They are shrubs or small trees, with inflorescences borne in the axils of the simple, petiolate, oppositely-arranged leaves. The flowers are arranged in cymes, and each is pentamerous. The Hawaiian endemic genus Labordia has been included in Geniostoma by some authors. These two genera have been grouped together in the family "Geniostomaceae", but are considered by the Angiosperm Phylogeny Group to be part of a wider Loganiaceae.