I came across this and instantly added it to the gardens here at Beech Street, basically because Black and Blue Salvia is a poor excuse of a plant.............And before anyone gets there panties in a bunch, hear me out. Black and Blue Salvia is not a hardy plant here and nurseries need to stop telling us it is and selling like it is (you know who you are, I have seen your tags and a zone 7b it is not). I went through 2 plants and my gardener neighbor went thru 3, enough said!
Clematis tubulosa is native to central and northern China. Woody based, non-climbing sub-shrub with erect black stems, 3' to 4' width and same in height and 1" X 1" fragrant flowers, yes fragrant flowers. Attractive, fluffy seed heads like other Clematis and the foliage is also scented. This is a plant to add to a garden.
USDA hardiness zone 5a to zone 9b