Pollinator and flower morphology interact to influence pollen receipt

Abstract

Pollinators are important drivers of floral divergence and speciation in plants. Here we investigate the effects of floral trait variation and trait matching on pollen receipt in two different plant species, Tritoniopsis revoluta (Iridaceae) and Nerine humilis (Amaryllidaceae) each visited by long-proboscid nemestrinid flies and solitary bees across their ranges. Using single visits by pollinators to flowers in populations with experimentally increased variance in floral morphology, we demonstrate that pollinators with different morphology affect pollen receipt differently through their interactions with floral traits. This study provides details of how the mechanical fit between floral and pollinator morphology may drive floral divergence through its effects on pollen deposition, both within populations using multiple pollinators and between populations with contrasting pollinators.