Asiatic dayflower (Commelina communis) is a sprawling annual recognized by its two brilliant blue upper petals and much smaller pale lower petal. Native to East Asia and now widespread across eastern North America, it favors moist ground, woodland edges and partly shaded places.

The flowers are edible, as are the tender young leaves and shoots when cooked. In East Asia, the plant also has a long history of use as a source of blue pigment. Individual flowers are fleeting—opening in the morning and often fading by afternoon—which gives the plant its common name.