Swamp dayflower (Murdannia keisak) is not a member of the genus Commelina where the true dayflowers belong, but it is in the same family Commlinaceae. It closely resembles the more familiar dayflowers. Swamp dayflower lacks the modified leaf called a spathe enclosing the flower of the members of Commelina, the other dayflowers.

The alternate arrangement of the leaves is typical of all of the common dayflowers including swamp dayflower. Here the absence of a spathe is obvious as well as the long stalk or peduncle that supports the flower. The flowers of swamp dayflower are solitary, another difference between it and the other dayflowers.