A large tree with a rough greyish bark, the twigs being brittle at the base; the leaves are pubescent on both surfaces and finely serrulate; it hybridizes with other species of Salix, it flowers in April and May and the bark is easily separable throughout the summer; flowers and leaves appear coincidently from March to June.
The bark contains up to 13 per cent of tannin as its chief constituent, together with a small amount of salicin.