Flowering vines add beauty to your garden and some, like the hummingbird flower, attract unusual wildlife. They can be planted to grow up a trellis or the side of a shed or garage. There are over a dozen different varieties of flowering vines in the United States, and approximately half of them have purple flowers. The key to identifying the species of a vine is by examining the flowers, petals and vines of the plant.
Examine the flowers and count the petals. Purple passion flowers have a large blossom with many tiny petals that have feathery ends. whereas morning glories can have between five petals that form a star, or 12 that form a complete circle.
Feel the texture of the leaves and look at their shape. Hyacinths have solid leaves that are rounded on the stem side and come to a point at the end. They are shiny and have a waxy texture. The leaf of the purple trumpet vine resembles an elephant's head: the base nearest the vine has two rounded sections that are the "ears" and the leaf that narrows in the center to a pointy "trunk."
Check the thickness of the vine. Moonflowers have narrow, dark-green vines that curve, while hummingbird flower vines are thin, bright green and grow straight.