One of those willows (Salix) that flower in spring.
(2004-04-06)

Incidentally, there are thirty-odd species of Salix in this country and thirty-odd hybrides which makes it a mess. They come in all sizes, the smallest one is the Least Willow (Salix herbacea) that protrudes less than an inch above the ground in the mountains. (Okay, there is also the similar, but less common Polar Willow (S. polaris)).