THE GOLDEN BOUGH

Seen from a distance the whole pussy willow tree shines golden.

These are the male flowers and the gold is pollen.  The female flowers are on separate female trees and look like little green hedgehogs.  Although insects do visit the male flowers for the pollen, they are not very interested in 'green hedgehogs' so this species mostly relies on the wind for pollination.  

The male flowers will drop to the ground when their job is done, but the female ones will develop into fluffy seedheads.