Pollination biology and pollinators of Conradina etonia (Fabaceae), a federally endangered plant in Florida

Etoniah False Rosemary, Conradina etonia, is a federally listed endangered perennial plant in the plant family Lamiaceae. Endemic to Florida, it is found only in Etoniah Creek State Forest (ECSF) in North Central Florida. To date, no studies have been done on the pollination or reproductive requirements of this endangered plant or its most effective insect pollinators. In accordance with the Species Status Assessment, our research aims to understand Conradina etonia’s pollination biology. including its overall pollination requirements, degree of self-compatibility, degree of pollinator dependence, and degree of pollen limitation. Conradina etonia showed a low degree of self-compatibility and selfing; seed set was over 100% higher in hand cross-pollinated and open treatments as compared to hand self-pollinated and pollinator-excluded treatments. Conradina etonia was also pollen limited in the field, with a 22% increase in seed set in pollen-supplemented treatments versus those only open to pollinators. The dominant insect visitors were bumble bees and nectar robbing carpenter bees. Small halictid bees and butterflies (swallowtail, sulfur, skipper, and gulf-fritillary) were also observed visiting. Bumble bees were effective pollinators and to a lesser extent so were carpenter bees, with both producing seed after visiting. This study provides a better understanding of Conradina etonia’s reproductive biology and will contribute to the success of its conservation efforts.