Thunbergia has been called “the most gorgeous vine in the world” by some. This blooming, twisted vine looks like Morning Glory from a distance, and the flowers are similar up close. Its common name of clock vine is derived from the fact that it is wrapped clockwise around support.
The Blue Trumpet Vine, Sky Flower, or Sky Vine are other common names. This evergreen, vigorous vine is native to Myanmar, Bangladesh, Nepal, India, and China. Thunbergia grandiflora is a vine in the Acanthaceae family. There are 100 to 150 species of flowering plants in the Thunbergia genus.
Thunbergia grandiflora is a curvilinear, tropical evergreen climbing plant with woody stems. In frost-free areas, it grows 15 to 30 feet long. When cultivated as an annual plant, it will grow 6 to 8 feet long in a single season. The heart-shaped to elliptical dark green leaves (up to 4 to 8 inches long) are clad with soft hairs. The trumpet-shaped flowers (up to 3-inches) are lavender –blue with a yellow throat. Flowers appear in clusters (racemes) or singly in summer through early fall. In tropical climates, the flowers bloom year-round.