The reflectance on the surface of the marble berry is truly mesmerizing.
We tend to think that the most brilliant and reflective materials on the planet can only be the product of the human intellect, such as mirrors or some extremely polished minerals. But in reality, nature already has its own mirrors: the silver beetle is the faithful sample of this, although it is not the only one, among the world of plants is the African plant that takes home the title of the brightest living matter in the world.
With the scientific name Pollia condensata and commonly known as the ‘marble berry,’ this plant species inhabits the forests of Central Africa. It grows about 60 centimeters tall and has large, smooth, narrow leaves. It is a perennial plant, which means it does not depend on seasonal changes to grow, but can always be seen as green and does not die in winter.
Its flowers are pale pink or sometimes whitish, but what catches the eye is its fruit. Clusters of up to 40 berries sprout from the plant, which is characterized by an electric blue color, and if you look closely, the reflectance of their surface is truly mesmerizing.
While iridescence is not a rare thing in nature, just think of butterflies, beetles, or even hummingbirds, it is extremely rare in plants.
The surface of marble berry fruits is smooth and reflective, just like a mirror. This is because just below its surface are a series of specialized cell layers composed of cellulose fibers. Each one of them is responsible for reflecting a narrow wavelength of light, which is also perfectly arranged so that each one can reflect light like a sieve. Thanks to this, exceptional colors are produced that give it its electrifying bluish appearance due to the effect known as Bragg reflection.
The plant uses this mechanism to attract the attention of birds, who approach intending to eat them. However, it is not an edible fruit but relies on the birds to chew them and then spread their seeds everywhere. This is how they ensure their survival.
The berries are only about 4 millimeters in diameter, but this surface area is enough to earn them the title of the most brilliant living matter on the planet. There is no other material with such reflective capacity; that is why they are so beautiful.
Story originally published in Spanish in Ecoosfera