PubMed · 2026-06-08
Crape myrtle flowers have two types of stamens: one set that feeds bees and another that actually pollinates. This study shows that both the shape of the flower and the timing of pollen release work together to match specific bee species — large carpenter bees get the pollinating pollen at the right time and in the right place, while smaller honeybees mostly just collect the food pollen.
Feeding pollen had lower male fertility than pollinating pollen, confirming the two stamen types serve distinct roles in reproduction.
Large carpenter bees matched floral morphology and deposited pollinating pollen dorsally (on their backs), achieving higher pollen transfer efficiency than honeybees, which accumulated feeding pollen ventrally.
Pollinating anthers began dehiscing early morning, coinciding with peak carpenter bee activity, while feeding anthers opened later — a temporal division that governs pollinator encounter frequency.
