"Why Understanding Blue Flowers is Crucial for Bees" by Adrian Dyer
A history of fascination
A preference for blue is common around the world today, and was found in many ancient cultures. The combination of this preference and the rarity of blue pigment in nature means the human search for blue has left a surprisingly large trail through history.
The ancient Egyptians were fascinated with blue flowers such as the blue lotus, and went to great trouble to decorate objects in blue. They used an entrancing synthetic pigment (now known as Egyptian blue) to colour vases and jewellery, and semi-precious blue gemstones such as Lapis Lazuli and turquoise to decorate important artefacts including the Mask of Tutankhamun.
Blue dye for fabric is now common, but its roots lie in ancient Peru, where an indigoid dye was used to colour cotton fabric about 6000 years ago. Indigo blue dyes reached Europe from India in the 16th century, and the dyes and the plants that produced them became important commodities. Their influence on human fashion and culture are still felt today, perhaps most obviously in blue jeans and shirts.
Renaissance painters in Europe used ground Lapis Lazuli to produce dazzling works that captivated audiences.
Today, many blues are created with modern synthetic pigments or optical effects. The famous blue/gold dress photograph that went viral in 2015 not only shows that blue can still fascinate - it also highlights that colour is just as much a product of our perception as it is of certain wavelengths of light.
Why do humans like blue so much?
Colour preferences in humans are often influenced by important environmental factors in our lives. An ecological explanation for humans' common preference for blue is that it is the colour of clear sky and bodies of clean water, which are signs of good conditions.
Besides the sky and water, blue is relatively rare in nature.
What about blue flowers?
We used a new online plant database to survey the relative frequencies of blue flowers compared to other colours.
Among flowers which are pollinated without the intervention of bees or other insects known as abiotic pollination, none were blue.
But when we looked at flowers that need to attract bees and other insects to move their pollen around, we started to see some blue.