Clematis macropetala (northern China to eastern Sibiria)
Habit: Petiole climber/trellis climber, 2-2.5 m tall and wide; moderately growing, partially dense and mat-like, thin arches, occasionally loosely overhanging shoots.
Flowers: Soft violet-blue with light centre; May to June.
Fruits: Silky, silvery, feathery syncarpy.
Leaves: In pairs of threes, dark green; ovoid; pale yellow in autumn.
Demands: Shady to slightly shady, sensitive to heat, do not plant on south-facing walls, prefers cool areas with high humidity, frost hardy.
Soil: Moist to fresh; slightly acidic to moderately alkaline, in all well drained substrates, not growing much on heavy soil.
Hardiness: Zone 6a