(CN) — Researchers from the University of Cambridge's Department of Plant Science say the Venice mallow hibiscus flower alters its cuticle layer to craft microscopic patterns that help reflect iridescent light for bees to see. In previous studies, small petal ridges have been observed on the flowers but not explained.
"Patterns formed at the microscopic scale can fulfill a range of functions, from communication with pollinators to defense against herbivores or pathogens. They are striking examples of evolutionary diversification and by combining experiments and computational modeling we are starting to understand a little bit better how plants can fabricate them," said study author Edwige Moyroud in a press release.
In short, the hibiscus petals "buckle" their cuticle to create a blue-halo light effect for bees. Plant cuticle layers have a mechanical element critical to this process. The structure change causes the petal surface to wrinkle and create microscopic ridges — also called nanostructures, which are tiny, ranging from 400 to 1,000 nanometers in length. The study also indicates that the flowers can isolate the texture change in some regions of their petals.
Without chemical engineering, such texture change would be impossible.
"Species that are closely related but that grow in different geographic regions can have very different petal patterns," noted Beverley Glover, the lead researcher.
Glover and her team were the first to identify the buckling behavior in a study published in 2021, which used a robotic system to identify the mechanical properties of plants. The same study showed that plants can instantaneously induce the buckling effect and that it is not a slow, biological process but rather genetic.
"Understanding why petal patterning varies and how this might affect the relationship between the plants and their pollinators could help to better inform policies in future management of environmental systems and conservation of biodiversity," Glover explained.
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