Goat Willow is a tree which can grow up to 10 metres tall. In spring the catkins appear before the leaves: the male catkins have brown scales which are initially covered in soft silvery-white hairs, giving an alternative name of Pussy Willow, with golden-yellow stamens appearing afterwards. The female flowers consist of downy grey-green ovaries with two stigmas at the top.
Goat Willow is very similar to Grey Willow, which has very similar flowers, although the stamens of Grey Willow are more orange in colour. The main difference is in the leaves, which are rounder in Goat Willow than in Grey Willow.