Phenological mismatch between Corydalis ambigua flowering and bumblebee queen visitation was observed during years with early snowmelt and warm spring temperatures. C. ambigua populations at different locations experience site-specific snowmelt conditions and bumblebee compositions, which may drive ecotypic adaptation of flowering traits, creating variations in sensitivity to phenological mismatch.
   We conducted common garden experiments to determine genetic variation in C. ambigua flowering traits. Flowering onset of natural populations and bumblebee visitation were observed at five research plots in 2022. Seed set of C. ambigua was measured across all sites from 2020 to 2022. Common garden experiments revealed sequential flowering of transplanted C. ambigua from different research sites, suggesting genetic differences in flowering traits. Bumblebee abundance was low in 2022, which is reflected in low seed set at several sites. At one site, visitation by exotic Apis bees seemed to reduce pollen limitation. C. ambigua seed set showed significant variation across sites and years.
   Our results suggest that the responses of C. ambigua phenology and seed set to climate change are influenced by ecotypic variation in flowering traits and site-specific pollinator compositions. Flowering traits are adapted to local conditions to maintain temporal synchrony of flowering onset and pollinator emergence.