Pollinator assemblage and pollen load differences on sympatric diploid and tetraploid cytotypes of the desert-dominant Larrea tridentata.

Our data are consistent with cytotype-specific bee visitation and suggest that pollinator behavior contributes to reduced diploid-tetraploid mating. Differences in bee visitation and pollen movement potentially contribute to an easing of minority cytotype exclusion and the facilitation of cytotype co-occurrence.