Nesocodon is a monotypic genus of flowering plants within the family Campanulaceae. The sole species is Nesocodon mauritianus, formerly known as Wahlenbergia mauritiana, which is endemic to the island of Mauritius. It was the first plant ever discovered to produce red-colored nectar. It was originally thought to have been pollinated by birds, however, recent investigations have demonstrated that day geckos (Phelsuma ornata) are the preferred pollinator of these flowers whereas birds function as nectar thieves. The introduced red-whiskered bulbul (Pycnonotus jocosus) robs it of its nectar. It is closely related to Heterochaenia from the Mascarene Islands, but has single flowers rather than panicles of several.