Clematis potaninii

Clematis potaninii, the old man's beard, is a species of flowering plant in the family Ranunculaceae, native to Tibet and central China. A deciduous woody vine, in the wild it is found climbing on slopes and in forests, particularly forest edges, at elevations from 1400 to 4000 m. Its cultivar 'Summer Snow', also known as 'Paul Farges', has gained the Royal Horticultural Society's Award of Garden Merit.