mini-Willow but which species??

mini-Willow but which species??

Observation - mini-Willow but which species??. Description: Very small bush (Willow) with spreading branches, growing in heathland in small ditch. Height only about 1m. Bright yellow flowers. Unopened flowers (?) are orange.Flowering before the leaves emerge.

Very small bush (Willow) with spreading branches, growing in heathland in small ditch. Height only about 1m. Bright yellow flowers. Unopened flowers (?) are orange.Flowering before the leaves emerge.