|'Violacea Plena', also known as 'Double Black Dragon' and 'Yae Kokyuryu', has double flowers which are violet in color. This is a popular, aggressive, flowering vine bearing pinnate leaves with up to 19 lance-shaped leaflets, each up to 3 inches long. Top choice for covering arbors or spilling over fences. Cherished for its 12 inch long clusters of fragrant, white to violet-blue flowers suspended along branches in spring. Flowering is not as spectacular as Chinese Wisteria due to prolonged season of bloom. Can become quite large.