Bell-shaped, slightly scented, dark blue flowers with pale yellow anthers.
The International Register and Checklist 2002 gives the parentage of this form as 'unknown'. The Toomey and Leeds Illustrated Encyclopedia of Clematis gives viticella x integrifolia (1835) and suggests that the form was possibly raised by Henderson of Pineapple Nursery, England.
This is not the same cultivar as x diversifolia 'Hendersonii' which, although extremely similar in other respects, is a taller plant.