Thunbergia grandiflora, commonly known as the blue trumpet vine, is native to northern India. Like other climbing vines, it needs space to attain mature size and habit. Hard pruning to control the size significantly reduces flower production. Flowers are more lavender than blue.

This genus was named in honor of Dr. Carl Peter Thunberg, who traveled and collected extensively in Java and Japan at a time when both of those countries were not friendly to outsiders.