Format: ORAL

Benoit Loeuille1, Oriane Hidalgo2, Carolina M. Siniscalchi3, Olivier Maurin1, Raquel Negro1, Jennifer Mandel4, William Baker1

1: Royal Botanic Gardens, Kew, UK 2: Institut Botànic de Barcelona, Spain 3: Mississippi State University, USA 4: University of Memphis, USA

The Compositae (or Asteraceae) are one of the largest flowering plant families with c. 1630 genera and c. 24700 species. They are distributed worldwide and display an amazing morphological diversity. Despite the challenging size of the family, molecular phylogenies have recovered a fairly consistent tribe-level backbone, which resulted in the current classification with 16 subfamilies and 51 tribes. However, up to now, phylogenomic studies have included less than 16% of the generic diversity of the family. Here, we present a robust phylogeny including c. 90% of the genera of Compositae and all subtribes but one, based on combined data from two different probe sets (Angiosperms353 and Compositae1061). The monophyly of the family is challenged by the position of Calyceraceae as sister group of Barnadesioideae in some of the inferences. The evolutionary relationships between the main lineages are mostly in agreement with previous phylogenomic studies, except for Hecastocleidoideae emerging as sister to the clade Gochnatieae + Wunderlichieae + Cyclolepis and Tarchonanthoideae as sister group of Carduoideae (not Dicomeae). A few tribes are polyphyletic under their current circumscription (Wunderlichieae, Neurolaeneae, Bahieae, Madieae). The evolution of Compositae is marked by at least ten whole genome duplication and numerous hybridisation events, which may explain the incongruences found between different datasets and methods of phylogenomic reconstruction (e.g., coalescent-based Astral vs. concatenated supermatrix). This phylogeny will allow new insights about morphological evolution, diversification, and biogeography of the Compositae.