Concerted changes in flower morphology and pollinators provide strong evidence on adaptive evolution. Schizanthus (Solanaceae) has zygomorphic flowers and consists of 12 species of annual or biennial herbs that are distributed mainly in Chile and characterized by bee-, hummingbird-, and moth-pollination syndromes. To infer whether flowers diversified in relation to pollinator shifts, we traced the evolutionary trajectory of flower traits and visitors onto a phylogeny based on sequence data from ITS, waxy, and trnF/ndhJ DNA. Maximum-likelihood ancestral reconstruction of floral traits suggests that ancestral Schizanthus had a bee-pollination syndrome. The hummingbird syndrome evolved in S. grahamii, a high elevation species in the Andes. The moth syndrome evolved in the ancestor of three species that inhabit the Atacama Desert. Results of mapping flower visitors onto the phylogeny show that the shift from bee to hummingbird pollination concurred with a shift in pollinators as predicted by the syndromes. However, the same pattern was not found for the moth syndrome. Visits by moths were observed only in one of the three moth-syndrome species, and at a very low rate. This mismatch suggests either anachronic floral characters or maintenance of rare, imperceptible moth pollination backed up by capacity for autonomous selfing. Overall, results suggest that diversification of flower traits in Schizanthus has occurred in relation to pollinator shifts.

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To assess whether floral integration patterns result from the action of pollinator selection on functionally related traits, we compared corolla integration patterns in eight Schizanthus species differing in pollination systems and in their degree of pollinator dependence across a molecular phylogeny. Integration patterns differed among species and these differences were not related to their phylogenetic relatedness. When the putative original function of some corolla traits was lost in pollinator‐dependent species, the integration among nonfunctional characters and the rest of the corolla traits was disrupted. This pattern was not presented in species adapted for late autonomous selfing, which exhibited higher corolla integration than their pollinator‐dependent relatives. These results suggest that corolla integration in pollinator‐dependent species was shaped by pollinator‐mediated selection. Decoupling of nonfunctional traits in these species may result from a relaxation of correlational selection or from selection acting against a default covariation provided by genetic and developmental connections.

AimThe relationship between the proportion of species with an entire leaf margin (pE) and mean annual temperature (MAT) is one of the most powerful tools for estimating palaeotemperatures. However, phylogenetic and phytogeographic constraints on this relationship have remained unexplored. Here we investigate the pE-MAT relationship for modern floristic assemblages from southern South American forests, assess its conformity to other models and test for the existence of historical constraints on pE-MAT models. Location South America.Methods We used samples from 30 sites located in Chile between 32°and 44°S to test for a pE-MAT relationship and compared it with four regional models. We assessed the reliability of these models for predicting MAT from instrumental records in eight modern temperate-forest localities in Chile. Additionally, palaeotemperatures for Cenozoic fossil floras were estimated. To assess historical constraints in pE, we measured the phylogenetic signal in leaf margin type and the association between leaf margin and phytogeographic affiliation, defined by the distribution of genera. ResultsWe found a significant pE-MAT relationship for Chilean forest species that differed from Australia and Northern Hemisphere models, but not from tropical South America (TSA). Temperatures for southern South American localities predicted from the new regional model -combining Chilean and TSA datasetswere more accurate than those from previous models. We also showed that leaf margin type has a strong phylogenetic signal, which was further confirmed by the highly significant effect of phytogeographic element on leaf margin type. Main conclusionsDifferences between the Chilean and other regional models are explained by historical legacy, as Chilean leaf margin types are strongly affected by phylogenetic closeness and phytogeographic elements. We highlight that leaf margin analyses should be conducted within the context of a flora with a shared history. Thus, we propose a new model for South America to estimate palaeotemperatures for regional fossil floras.