The Goat willow (Salix caprea) or Saileach dubh in Irish is inconspicuous for most of the year. However, in March it displays its male catkins which are covered in golden pollen. These make it stand out in the hedgerows before it fades back into obscurity for another year (1).
This willow displays its male catkins to the passing winds so that its pollen will be blown onto the long, green female catkins which will be displayed on a different tree. They do this before they come into leaf to take full advantage of the wind.
The female catkins develop later in the year into light, woolly, tufted seeds which again are scattered far and wide by the wind (2).
These willows provide abundant pollen and nectar for early flying bumblebees and hoverflies. They mostly eat nectar themselves to give them energy. The young are fed mostly with pollen to provide them with the proteins necessary for growth.
This is one of our commonest willows and is often called ‘sallow’, ‘sally’ or ‘pussy willow’. The latter name is given to it because the male catkins resemble cats’ paws.
It can be confused with the Grey willow (Salix cinerea) or Saileach liath in Irish. They can be distinguished apart by looking at the leaves and twigs. The leaves of the latter are much longer than they are broad, and the twigs are a reddish colour; the leaves of the former are nearly round, and the twigs are brownish.
Aspirin, the well-known painkiller, is derived from salicin which is a compound found in the bark of all willow trees.