CAPITULUM: The International Compositae Alliance Newsletter

The more the merrier: The Cardueae Radiations Group and the power of team work.

Alfonso Susanna

https://orcid.org/0000-0003-4717-9063

DOI: https://doi.org/10.53875/capitulum.01.1.01

Keywords: Jurinea, Saussurea, subtribal classification, target-enrichment

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Abstract

Tribe Cardueae (Compositae) has long resisted a stable subtribal classification, in large part because of extensive morphological diversity, the presence of multiple megagenera (e.g., Cousinia, Cirsium, Jurinea, Saussurea, Centaurea), and the limited resolving power of traditional marker sets for rapid radiations. Building on recent advances in target-enrichment sequencing for Compositae, we initiated in 2017 a coordinated effort to address two major radiations in the tribe—Saussurea and Jurinea—where exhaustive sampling across vast and logistically challenging regions is essential. Here we describe the rationale and development of the international Cardueae Radiations Group and summarize how collaborative sampling and shared taxonomic expertise, coupled with Hyb-Seq analyses, have enabled (i) evaluation and optimization of analytical pipelines (concatenation vs. coalescent approaches), (ii) a substantially revised, morphologically coherent subtribal classification of Cardueae (expanding from five to twelve subtribes, including several newly recognized), and (iii) clarification of generic limits in Saussureinae, reducing numerous segregates to three principal genera. We highlight how plastid–nuclear discordance, likely linked to historical hybridization, contributed to earlier classification instability, and we outline prospects for resolving remaining taxonomic challenges in the tribe through continued teamwork and phylogenomics.