Clematis 'Sylvia Denny', a moderately fast growing, dwarf, compact, deciduous, fully hardy, climber with semi-double, pure white flowers and mid-green foliage suitable for containers. The semi double flowers appear early summer and a second flush of flowers which are single and smaller appear late in summer. It thrives best in full sun. Height 150-200cm. Supplied in a 3-4 litre pot.