Drosera erythrorhiza, the red ink sundew, is a perennial tuberous species in the carnivorous plant genus Drosera that is endemic to Western Australia. It grows in a rosette and is distinguished from the other species in section Erythrorhiza by its many-flowered cymose inflorescences with up to 50 individual flowers. D. erythrorhiza was first described by John Lindley in his 1839 publication A sketch of the vegetation of the Swan River Colony. In 1992, N. G. Marchant and Allen Lowrie described three new subspecies, thus also creating the autonym D. erythrorhiza subsp. erythrorhiza. The subspecies were separated from this variable species mostly by leaf morphology and distribution.