Definitions for dayflowerˈdeɪˌflaʊ ər
Random House Webster's College Dictionary
any of various plants of the genus Commelina, of the spiderwort family, usu. bearing clusters of small blue flowers that open only during the day.
Origin of dayflower:
any plant of the family Commelinaceae
Any of several plants, of the genus Commelina, whose flowers last only a day
a genus consisting mostly of tropical perennial herbs (Commelina), having ephemeral flowers