Scientists at the University of Cambridge have found that mechanical bending of petals produces rainbow patterns visible to bees.
Flowers use different strategies to lure pollinators. One of them is the chemical coloring of pigments that are on the petals and shimmer when moving. The authors of the new work believe that this is one of the most important methods of attracting pollinators.
The new optical effect, which the authors discovered, is created using a complex pattern of nanoscale ridges on the surface of the petals. They refract light and, as a result, colors shimmer beautifully. It’s all about the bending of the petal, which sways in the wind and attracts the attention of pollinators.
The same effect can be seen on the surface of CDs or soap bubbles.
In order to understand in more detail how the basis for this type of pollinator attraction is formed, the authors studied the grooves of the petals on hibiscus flowers: they appear during the growth of the petals.
During the experiment, the researchers stretched young hibiscus petals, on which scallops began to appear. This means that it is the bending of the petal that causes this effect.