The buckeye tree has an unusual flower arrangement. The flowers aren’t too showy, and seem to be in a configuration that makes landing on them difficult for bees. Yet they must have pretty good nectar and pollen rewards, because the bees spend a lot of time hovering near them in order to get their meals. Bumblebees and honey bees hang around them. I don’t see many of the smaller bees around them, however–they seem to prefer other flowers.