LAUSR

Abstract Here, we describe and illustrate Enceliabalandrasp. nov., a new species of Compositae from the Baja California Peninsula. It is rare and known only from the rocky hills around Puerto Balandra and Pichilingüe, inside the bay of La Paz, in the State of Baja California Sur, Mexico. We determine that this new species has affinities with Encelia, based on its suffruticose woody habit, neuter ray florets and compressed disc cypselae with a cleft apex. The taxonomic placement within Encelia is supported by nuclear ribosomal sequence data from two regions, ITS and ETS. We also present detailed photographs, a conservation assessment and a dichotomous key to the Encelia of the southern Baja California Peninsula. Finally, we discuss the uniqueness of Enceliabalandra amongst peninsular Encelia and its potential significance for understanding the enigmatic biogeography of this ecologically important genus.