Flower patterns are adapted for detection by bees.

We have demonstrated previously that honeybees use brightness vision mediated by green (or L-) receptor to detect targets from a long distance. They detect circular targets having a dim, for the L-receptor, centre and bright surround from a longer distance than targets having bright centre and dim surround. Here we show that a majority of bee-pollinated flowers have a centre that, for the L-receptor, is dim with bright surround, i.e. have patterns that are easy for a bee to detect. Flowers with dim for the L-receptor surrounds tend to be larger than those with bright surrounds, indicating that flowers compensate for the impaired visibility of their patterns by increasing the size of their displays.