Willow tree reaching up to 20 meters in height, often pollardedA pruning system involving the removal of the upper branches of a tree, which promotes the growth of a dense head of foliage and branches. More, found in Europe along riverbanks and in wet woodland. 
Cavities originated by pruning provide nesting sites for many bird species (such as the hoopoe, great tit and owl) and its thin, flexible branches can be used to create baskets.