A Common Flower with A Unique Bidirectional Color-changing Ability was Newly Discovered
Published:23 Dec.2022    Source: University of Tokyo

One of the most appealing things about flowers is presumably the wide array of shapes, sizes and, of course, colors they come in. But did you know that some flowers can change their colors? Although it's not all flowers, this trait has been observed in hundreds of different species for at least a number of decades. It's thought that color-changing flowers do so because it signals to pollinating insects that the flower is ready to supply nectar or pollen which rewards them. And all examples of color-changing flowers found have been unidirectional: Once the color has changed, it does not change back. However, A plant common to Japan, Causonis japonica, is the first to show a newly discovered trait. 

The flowers of Causonis japonica can change color depending on the stage of its maturation cycle, and then change back to its original color. Although many flowers have been shown to change color depending on their maturation phase, Causonis japonica is the only known example of bidirectional color change. Professor Hirokazu Tsukaya of Tokyo University was very surprised to see the color of Causonis japonica flower changed, and then changed again and again.
The pigments involved in the colors are related to nutrient-rich colorful vegetables, so understanding the flowers' color-changing tricks could have downstream applications in improving nutrient yields in certain food crops.