A new species, Pentacalia poeppigiana (Asteraceae, Senecioneae), known to date from Lima department in the western slopes of the Peruvian Andes, is described and illustrated. Due to its characteristics, it appears distantly related to the rest of congeners, but a close relationship with Senecio tingoensis seems likely. As suggested by preliminary molecular studies, the new taxon should be transferred to a new genus that would also include S. tingoensis and perhaps some other 'anomalous' Andean Senecio species. Further remarks on the morphological affinities, geographical distribution, ecological preferences, and conservation status of P. poeppigiana are included.