Clematis vitalba (also known as Old man's beard and Traveller's Joy)
According to Wikipedia, a climbing shrub with branched stems, deciduous leaves, and scented greeny-white flowers with fluffy underlying sepals. The fruits have an overlying silky appendage lengthwise on the plant.
The seeds are disseminated by the wind. Unfortunately, it has a bad name and in In New Zealand it is declared an "unwanted organism" and cannot be sold, propagated or distributed. It is a threat to native plants since it grows vigorously and forms a canopy which smothers all other plants. It reminds me of the frivolous hats as worn in the fifties.