In 1860 Benedict Roezl discovered a plant in northwestern Guerrero, Mexico which he described as Ghiesbreghtia dentata. Specimens raised from seeds of his collection were known in Belgian gardens as “Agave Ghiesbreghtii dentata,” and Jacobi (1865) described them as A. debaryana. This is the oldest name for A. pedunculifera, described by Trelease (1920) and, as a comparison of the characters shows, this plant is nearly identical with A. attenuata Salm-Dyck (1834). A new combination is therefore made: A. attenuata Salm-Dyck ssp dentata (Roezl) Ullrich. The neotype is Rzedowski & McVaugh #289 (43 km W of Chilpancingo, Guerrero, 2000 m; 31.1.1965; ECBN isoneotype at MICH). In the future it may be possible to distinguish the northern populations along the Sinaloa-Durango border as subspecies pedunculifera.