Green on green
Colourful flowers stand out between the greenery. There are, however, green flowers. Now Spanish and American researchers show in Annals of Botany that those do stand out, at least for bees and flies.
‘A green flower is not noticed, and is pollinated by wind.’ That was long the believe. But there are green flowers that are indeed visited by insects. These flowers are not as inconspicuous for pollinators as they are for people. What are those insects seeing that were are not seeing? That the researchers decided to investigate.
By taking the sight of bees and flies as starting point, the researchers observed that green-yellow flowers are just as conspicuous as yellow flowers. They are not obscured by the greenery of the rest of the plant. Real green flowers turned out be more difficult to distinguish, especially for flies.
A pinch of yellow pigment makes flowers more conspicuous
To find out how these green flowers were noticed by bees and flies, the researchers studied another aspect of light. We are seeing both in colour and in shades of light and dark. For flies and bees the green flowers could be distinguished just on the shades of light and dark observed.
For being noticed it helps flowers to have a bit of yellow pigment. To give just that little bit of contrast. Still, plants have additional options to make their green flowers attractive.
Literature
José C del Valle, Melissa León-Osper, Carlos Domínguez-González, Mª Luisa Buide, Montserrat Arista, Pedro L Ortiz, Justen B Whittall, Eduardo Narbona, Green flowers need yellow to get noticed in a green world, Annals of Botany, 2024;, mcae213, https://doi.org/10.1093/aob/mcae213
Plant en Zo 