"It was true then: he had after all the shifting hue of the dewflower. She had heard about that. She had heard, albeit in general terms, that men were good at lying, that many a sweet word went into the pretense of love."
From "The Tale of Genji" by Murasaki Shikibu, translated by Edward G. Seidensticker (Penguin Books)
The bright blue petals of the dewflower, or dayflower, open at dawn and wither at dusk, making it a very suitable analogy for fleeting affections. On close inspection you will find a third petal, a small white one, lying below the stamens. This pretty plant is quite tough and is often seen thriving by roadsides.