ABSTRACT Aim We reconstructed the biogeographic history of Pappophorinae and tested whether the evolution of awns is associated with differences in species' geographic ranges. Location Americas. Time Period Miocene. Major Taxa Studies Pappophorinae (Poaceae: Chloridoideae). Methods We recovered a time‐calibrated phylogeny and detected a phylogenetic signal between awn length and number and the species extent of occurrence (EOO). Results and Main Conclusions The biogeographic model that best fits the evolutionary history of Pappophorinae retrieved an ancestral distribution in the Americas, from which the six current geographic areas arose mainly through long‐distance dispersal and, to a lesser extent, vicariance events. The Guiana Shield region (D) received the highest frequency of dispersal events from multiple areas and contributed only to dispersal toward the Caribbean (E). In contrast, the Caribbean received fewer dispersal events overall but was the only region that received dispersal from all other areas. Based on this pattern, we hypothesise that the Caribbean acted as an important route of colonization between North and South America. In addition, longer and more numerous awns are significantly associated with broader geographic distributions. Together, these results indicate that variation in awn morphology is associated with geographic range size and that historical dispersal processes contributed to shaping the biogeographic patterns of Pappophorinae across the Americas.
Couceiro et al. (Sun,) studied this question.