Clematis integrifolia

Clematis integrifolia is a flowering vine of the genus "Clematis". Like many members of that genus, it is prized by gardeners for its showy flowers. 
"C. integrifolia" bears nodding, urn-shaped blue flowers in summer that are 1.5 inches wide. It is a fairly short variety, growing only to 3 feet high. It is native to Europe and Asia; in the USA it grows best in American Horticultural Society zones 8 to 1.
Several popular hybrids have been made by crossing "C. integrifolia" with other "Clematis" varieties. "C." 'Hendersonii' is a cross with "C. viticella", and "C". 'Durandii' is a cross with "C. x jackmanii".