The Convolvulaceae, commonly called the bindweed or morning-glory family, is a cosmopolitan family of 50-65 genera and about 1500 species. Most people have a good idea of what morning-glories look like, with their climbing or twining stems and their large 5-lobed and funnel-shaped flowers that are structured like the aperture of a camera and unfoldl as they open. The leaves are alternate and simple, and many species have a milky sap. The Convolvulaceae is mostly a herbaceous family with some shrubs and trees, and takes its name from the Latin convolvere, "to wind," in reference to the winding character of the stem. The sweet potato (Ipomoea batatas) is a member of this family, and the seeds of some species have had medicinal uses as purgatives. The parasitic dodder has been considered by some taxonomists as a family member.