The impact of pollinator functional traits on pollination effectiveness is shaped by floral morphs in distylous plant species.

This article investigates pollination effectiveness (PE), measured as single-visit deposition (SVD) of compatible pollen, in insect pollinators visiting distylous common buckwheat (Fagopyrum esculentum Moench), which has two floral morphs: pin (long style, short stamens) and thrum (short style, long stamens). The study examines how SVD relates to insect morphological traits (body length, proboscis length), pollen loads on different body parts, and visit duration, revealing that larger body size and higher pollen loads generally increase SVD across species. Notably, pollinators with shorter proboscises are more effective on thrum flowers, indicating morphological trait-matching between pollinators and floral morphs influences pollination outcomes. Additionally, visit duration positively affects SVD on thrum flowers but not on pin flowers, highlighting differences in plant–pollinator interactions between floral morphs in this distylous species.