Mystery silvery-white-leaved tree

Mystery silvery-white-leaved tree

Observation - Mystery silvery-white-leaved tree - UK and Ireland. Description: I first thought this was a white-leaved willow, or perhaps a pear, but the flowers are neither of those. Strange 4-petalled yellow flowers with 4 stamens. Quite waxy looking. The silvery whiteness on the leaves is made of flattened plate-like hairs/sca

I first thought this was a white-leaved willow, or perhaps a pear, but the flowers are neither of those. Strange 4-petalled yellow flowers with 4 stamens. Quite waxy looking. The silvery whiteness on the leaves is made of flattened plate-like hairs/scales.
A small tree, presumably planted, on an urban recreation ground. Pungent smelling too.