Many living things, from chameleons to fish to squid, have the
ability to change their colour. But flowers? Yes, over 450
species of flower have the ability to shapeshift, altering their
colour and positions over the course of a day. The goal, as with
many aspects of a flower’s nature, is communication. The
secondary palette tells pollinators that a particular flower has
already been visited and not only needs no pollen but has little
nectar to offer as a reward. The visitor’s attentions (and the
pollen it carries) are directed towards needier flowers. The
legume Desmodium setigerum is one of these colour-changers. Its
small flowers, just a centimetre across, last for just a day and
start off with a lilac hue. When pollinating bees land on the
flower, their weight “trips” one of the petals and explosively
reveals the flower’s reproductive parts. After these visits, the
flowers’ top petal falls down, obscuring the anthers and stamen,
and the petals transform from lilac to white and turquoise. The
whole process