Brightest Thing in Nature: African Fruit Pollia Condensata
Biologists have discovered that the Pollia condensata fruit does not get its blue color from pigment but instead uses structural color – a method of reflecting light of particular wavelengths. Most colors around us are the result of pigments. However, a few examples in nature – including the peacock, the scarab beetle and now the Pollia condensata fruit – use structural color as well.
The scientists also discovered that each individual cell generates color independently, producing a pixilated or pointillist effect. This color is produced by the reflection of light of particular wavelengths from layers of cellulose in the cell wall. The thickness of the layers determines which wavelength of light is reflected. As a result, some cells have thinner layers and reflect blue; others have thicker layers and reflect green or red. The biologists believe that the plants invest in the complicated coloring structure as a mechanism for seed dispersal. Although the Pollia fruit does not provide any nutritional value, birds are attracted to its bright coloring – possibly as a means of decorating their nests or impressing their mates.