Marble glittering berry Pollia condensata
These beautiful tiny glittering berries, actually the shiniest objects in the world, belong to the plant Pollia condensata. But it’s more than their brilliance that makes these tropical fruits, native to Ethiopia, Tanzania and Uganda, noteworthy. The plant consists of special layer of cells that reflects light. And this gives the fruit its iridescent hues – a phenomenon known as structural coloration. “The optics are impressive,” Silvia Vignolini, co-author of the study, told Nature. According to her, there are no previous examples of this in nature. Despite having no nutritional value, the appearance of the berries attracts birds. Birds sometimes decorate their nests with the berries, in the process help spreading the seeds.
In addition to simply reflecting light of a specific wavelength, the helicoid structure also causes causes light of other wavelengths. Meanwhile, the wavelength converges to within a narrow range before being reflected, which appears to amplify the light. And this produces the perception of a very intense color. Physically, we know this process as “constructive interference”. As a result, a berry coloration is more intense than that of any other existing living organism. Total reflectivity is about 30%, which compares with the reflectivity of a standard silvered glass mirror. Besides, it is higher than that of any other known biological material.
The surface of the Pollia berry has a particularly smooth and transparent cuticular surface layer which reflects light in the same way a mirror does (specular reflection) and as a result makes the berry appear to have a high level of gloss
Marble glittering berry Pollia condensata
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