The factors that drive the evolution of specialized pollination systems are considered a central tenant of future research in the field of pollination ecology. We seek to bring further understanding to a poorly understood but taxonomically widespread specialized pollination system. Synchronous dichogamy, the synchronized temporal separation of sexual function, is found in Canella winterana, a woody tree species native to the West Indies and southern Florida. In this system all flowers within a plant bloom synchronously as functional females and after 24 hours they synchronously switch to functional males. In this way, pollen is dispersed away from the plant to other individuals in the environment. Theoretically, synchronous dichogamy should reduce the amount of self‐pollination in these plants, thus promoting the deposition of congeneric pollen via animal‐mediated pollen dispersal. However, there is little empirical evidence for synchronous dichogamy as a specialized pollination syndrome and little is known about how this affects the genetic structure of populations. The aim of this study is to bring further understanding to how this specialized pollination system promotes gene flow in populations of Canella by identifying the pollinator community associated with this plant. Findings from this research will influence conservation of Canella in the United States, which is endangered in part of its natural range in the Florida.
Results/Conclusions
Initial observations in the summer of 2014 and 2015 show that Canella had very few flowering individuals during the 2014 flowering season; 600 plants were observed in the Bahamas and southern Florida and only 8 plants were observed in flower or as having been in flower. Plants were always observed flowering in pairs at the edge of upland hammock habitats and were always found in in the same sexual phase. This finding suggests a strong potential for pollen dispersal away from the parent plant to other plants within populations or between adjacent populations. As such, these observations suggest that synchronous dichogamy promotes genetic admixture within and between populations. In addition, we observed two species of hummingbird, Calliphlox evelynae and Chlorostilbon ricordii, and the atala butterfly, Eumaeus atala, as potential pollinators of Canella. The atala butterfly was the most abundant pollinator observed during our pollinator observations. Microsatellite markers are currently being developed and will be used to compare the genetic structure of Canella populations in and between Florida and the Bahamas.