Mimosa foreroana, a new species of Mimosa sect. Mimadenia ser. Glanduliferae, is described and illustrated. It is apparently endemic to vereda Ijagüí, in the Department of Nariño, Colombia. This species is distinguished by a combination of characters, including minute glands on vegetative and reproductive structures, leaves with two to three pairs of pinnae and one to three pairs of leaflets per pinna, and short tub-shaped or trough-shaped nectaries near mid-petiole and close to the insertion of the pinnae and leaflets. In addition, scanning electron micrographs of the glands, a map of distribution, and a key to the species of Mimosa ser. Glanduliferae are presented.