Purple heart, a member of the spiderwort family, is one of the most common tropical foliage plants offered by garden centers for use in annual beds and baskets in the Midwest. Native to Mexico, this vine produced elongated, succulent, rich purple leaves that fold inward. The small pink flowers are produced at the ends of branches and are nestled in boat-like bracts. The plants will grow in sun or shade, although the color is more intense in sun. The stems root easily and may do so as they trail along the ground. There are about 70 species of spiderwort, with three native to the Chicago area.