Asiatic Day (Commelina communis, 鸭跖草).
Now (and every late summer), hundreds of these flowers spring up in wet shady places around Yuelu Mountain. The flowers only last for a day, but every day there will be new ones appearing. The flowers also have a long history of human use: they provided the blue colour in old Japanese woodblock prints and Traditional Chinese Medicine claims they have the effects of removing water, clearing away heat, cooling blood, and detoxification.
