typical (not double) daylily flower has
six perianth segments arranged in two rows. The three
inner ones are the petals, and the three outer ones
are the sepals. The term
may be used to refer to any of the six, because they are
relatively undifferentiated from each other as compared
to many other plants, such as roses. Also see: Petal, Sepal, Polymerous.
Photo: Pat Lovelend, used with permission.