Infrageneric classification of the Argentine species of Baccharis (Asteraceae, Astereae)

Abstract

The genus Baccharis is represented in Argentina by 96 species, the infrageneric classification of which is presented in this paper. A succinct summary of the history of Baccharis infrageneric taxonomy is provided. The 96 Argentine species are placed into 15 sections: Angustifoliae, Aristidentes, Baccharis, Caulopterae, Cuneifoliae, Cylindricae, Discolores, Molinae, Nitidae, Oblongifoliae, Paniculatae, Pedicellatae, Pseudobaccharis, Subliguliflorae -sect. nov.- and Trinervatae. These sections are briefly described, and a key to differentiate them is given. Twelve out of the 96 species are positioned into the
infrageneric classification system for the first time, whereas 42 species which had been previously classified are here relocated to other sections. Twenty-two generic, subgeneric, sectional and subsectional names are considered as new synonyms. The relationships among the sections are discussed.