The Asiatic Dayflower, Commelina communis, is a cute three petal flower with two upper blue petals and one lower white petal. The lower white petal is so thin or narrow that often it is not even noticeable. The two larger blue petals stand out like Mickey Mouse ears. Long stamens stand out and anthers are bright yellow. A sheath is underneath each flower as a sort of pocket.
In the photo above taken 6 June 2010, the thinner stem to the left of the larger stem on the right is that of the Asiatic Dayflower. Note the oval pointed leaves and the sheath that houses the flower until blooming time.
A related plant called Virginia Dayflower, Commelina virginica, has three blue petals and otherwise the flower appears the same as the Asiatic Dayflower. The Virginia Dayflower is native to Eastern North America, but it’s very rare compared to the alien Asiatic Dayflower.
Dayflowers are named appropriately as they bloom for only one day, so they’re no good for cut flower arrangements.
Leaves are linear-veined, pointed ovals that sheath the stem. These plants spread by laying down their stems and rooting at the leaf nodes. This reclining habit also helps to differentiate the Asiatic Dayflower from the native dayflowers, which grow in an erect posture.
Asiatic Dayflowers photographed here were growing along the upper west lane near blackberries in a partially shaded area with Spotted Touch-Me-Nots.
Much better pictures of the Asiatic Dayflower can be seen in an earlier post about it blooming in South-central PA.
Peterson’s Edible Plant Guide