Sinosenecio primulifolius (Asteraceae), a new species from Chongqing, China

Sinosenecio primulifolius, a new species from Chongqing Municipality, southwestern China, is described and illustrated. It is characterized by the scapigerous habit, ecalyculate capitula, Primula-like, membranous, palmately 7-veined leaves with large subdeltoid mucronulate teeth along the margins and conspicuous adaxial venation, and smooth, glabrous achenes with pappus. Phylogenetic analysis based on nrITS sequences places the new species in the S. oldhamianus–Nemosenecio clade of subtribe Tephroseridinae. This affiliation is further supported by its chromosome number, 2n = 48, and polarized and radial anther endothecial cell wall thickenings. Within this clade, S. primulifolius is phylogenetically allied with S. bodinieri, S. confervifer, S. nanchuanicus, S. tongziensis, S. fanjingshanicus, S. changii, and S. lichuanensis, but is readily distinguished from these relatives by its distinctive leaf morphology.