CAPITULUM: The International Compositae Alliance Newsletter

Baccharis L. (Astereae): From Nova Scotia to Cape Horn

Gustavo Heiden

https://orcid.org/0000-0002-0046-6500

Mauricio Bonifacino

https://orcid.org/0000-0003-0377-3853

DOI: https://doi.org/10.53875/capitulum01.1.02

Keywords: Asteraceae, Asteroideae, Baccharidinae, Compositae

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Abstract

Baccharis L. (Astereae, Asteraceae) is a large American genus currently comprising more than 440 accepted species and extending from Nova Scotia to Cape Horn. Despite its prominence and ecological breadth, the genus remains taxonomically challenging because of high species richness, frequent morphological convergence among lineages, and the recurrent use of variable vegetative traits in species delimitation. This paper provides a taxonomically oriented overview of Baccharis, summarizing diagnostic generic features, the principal morphological character systems used in identification, and major patterns of variation relevant to infrageneric classification. We review the geographic structure of diversity, highlighting South American centers of richness and endemism, and briefly discuss how distributional and ecological patterns intersect with species limits and group circumscription. The synthesis aims to provide an updated framework for recognizing and comparing Baccharis taxa, and to identify priority areas for future work, including revisionary studies in difficult species complexes, improved documentation of type material, and increased integration of morphology with molecular phylogenetic evidence.