Clematis is a genus of woody based perennials, mostly climbers with a twining habit, though some are grown as groundcover or as herbaceous plants.
They can be single or double, fragrant or unscented, compact or vigorous, in a wide range of shapes and sizes.
The flowering period varies from early spring to late summer.
Many spring-flowering cultivars produce a second flush of blooms after the main display has finished, and many have attractive silky seed-heads prolonging the period of interest.
Clematis can be grown against walls, fences, over pergolas and obelisks, or through other shrubs and trees.