A newly naturalized species, Utricularia graminifolia Vahl, has been found in north Taiwan. This Lentibulariaceae species, native to India, Ceylon, Burma, Tailand and China, was introduced to Taiwan for aquarium ornamental many years ago. The morphology of this species is very similar to U. bifida L., and is distinguished from the latter by its blue-purple corolla and longer linear leaves. A taxonomic treatment, color photographs, line drawings, and distribution from the wild were provided to aid in identification.