Pollination syndromes in a specialised plant‐pollinator interaction: does floral morphology predict pollinators in C alceolaria ?

Pollination syndromes are defined as suites of floral traits evolved in response to selection imposed by a particular group of pollinators ( e.g., butterflies, hummingbirds, bats). Although numerous studies demonstrated their occurrence in plants pollinated by radically different pollinators, it is less known whether it is possible to identify them within species pollinated by one functional pollinator group. In such a framework, we expect floral traits to evolve also in response to pollinator subgroups ( e.g., species, genera) within that unique functional group. On this, specialised pollination systems represent appropriate case studies to test such expectations. Calceolaria is a highly diversified plant genus pollinated by oil‐collecting bees in genera C entris and C halepogenus . Variation in floral traits in C alceolaria has recently been suggested to reflect adaptations to pollinator types. However, to date no study has explicitly tested that observation. In this paper, we quantitatively test that hypothesis by evaluating the presence of pollination syndromes within the specialised pollination system formed by several C alceolaria and their insect pollinators. To do so, we use multivariate approaches and explore the structural matching between the morphology of 10 C alceolaria taxa and that of their principal pollinators. Our results identify morphological matching between floral traits related to access to the reward and insect traits involved in oil collection, confirming the presence of pollinator syndromes in C alceolaria . From a general perspective, our findings indicate that the pollination syndrome concept can be also extended to the intra‐pollinator group level.