Pollinator behavior differs between female and hermaphroditic plants of Lobelia spicata. Lam. (Campanulaceae)1

Abstract

Abstract Female flowers of gynodioecious species (plants with either female or hermaphroditic flowers) are typically smaller with no reward for pollinators. We proposed and tested that pollinators (bees and butterflies) would visit female plants less frequently and visit fewer flowers for a shorter duration in a native prairie species, Lobelia spicata. We observed and quantified floral visitors exhibiting pollinator behavior in a population of L. spicata in a remnant tallgrass prairie located in central Illinois. We also quantified the number of seeds per fruit and fruits per plant. We found female plants have fewer visitors than hermaphroditic plants. Bees and butterflies, once on female plants, visited fewer flowers and spent less time than on hermaphroditic plants. Despite the lower number and shorter duration of visits, the females set more seeds per fruit. However, females did not consistently produce more seeds per plant, which is required to maintain females in the population.