Ambophily, the mixed mode of wind and insect pollination is still poorly understood, even though it has been known to science for over 130 years. While its presence has been repeatedly inferred, experimental data remain regrettably rare. No specific suite of morphological or ecological characteristics has yet been identified for ambophilous plants and their ecology and evolution remain uncertain. In this review we summarise and evaluate our current understanding of ambophily, primarily based on experimental studies. A total of 128 ambophilous speciesincluding several agriculturally important cropshave been reported from most major habitat types worldwide, but this probably represents only a small subset of ambophilous species. Ambophilous species have evolved both from wind-and insect-pollinated ancestors, with insectpollinated ancestors mostly representing pollination by small, generalist flower visitors. We compiled floral and reproductive traits for known ambophilous species and compared our results to traits of species pollinated either by wind or by small generalist insects only. Floral traits were found to be heterogeneous and strongly overlap especially with those of species pollinated by small generalist insects, which are also the prominent pollinator group for ambophilous plants. A few ambophilous species are only pollinated by specialised bees or beetles in addition to pollination by wind. The heterogeneity of floral traits and high similarity to generalist small insect-pollinated species lead us to conclude that ambophily is not a separate pollination syndrome but includes species belonging to different insect-as well as wind-pollination syndromes. Ambophily therefore should be regarded as a pollination mode. We found that a number of ecological factors promoted the evolution of ambophily, including avoidance of pollen limitation and self-pollination, spatial flower interference and population density. However, the individual ecological factors favouring the transition to ambophily vary among species depending on species distribution, habitat, population structure and reproductive system. Finally, a number of experimental studies in combination with observations of floral traits of living and fossil species and dated phylogenies may indicate evolutionary stability. In some clades ambophily has likely prevailed for millions of years, for example in the castanoid clade of the Fagaceae.

Reproductive systems and pollination modes (pollination by animals vs. wind) can switch within clades, and many species with an intermediate pollination mode (ambophily, pollination by animals and wind) exist. Here, we investigate the reproductive systems and pollination modes of two common Eurasian species from the Agrimonieae (Rosaceae) that occur in open habitats, Sanguisorba minor and Sanguisorba officinalis. Based on observations from literature, the flowers of both species are visited by insects, but due to flower morphology S. minor is commonly regarded as wind pollinated, while S. officinalis is classified as insect pollinated. By measuring floral traits, such as pollen grain and ovule number per flower, observing flower visitors in natural habitats as well as in the botanical gardens and conducting pollination experiments we found that the reproductive systems and pollination modes of the two species differ: Sanguisorba minor is commonly but infrequently visited by short‐tongued insects but is nevertheless exclusively wind pollinated. However, in contrast to most other wind‐pollinated species, S. minor is highly self‐compatible and even able to set seeds by autogamous selfing. Sanguisorba officinalis, on the other hand, is largely insect pollinated, but wind also contributes to seed set (⁓17% after insect exclusion). This species is able to set seeds by geitonogmous selfing but seed set is higher by outcrossing than by selfing. Thus, our study demonstrates another example of a plant species with small, open flowers arranged in large inflorescences that can be shown to be ambophilous. Further, the study will help to reconstruct the complex evolution of pollination modes in Agrimonieae (Rosaceae).