Aspirin is made of salicin which comes from Willow trees, like this Pussy Willows. It reduces inflammation and pain. Once, in a gallery, I put my hand in a paper bag filled with soft, smooth, silvery, velvet Pussy Willow buds and was soothed.

Those soothing things on Pussy Willows are their very young flowers. The fluff keeps them warm at the end of the winter while they are budding.
In a few days these fluffy buds will change. They will grow into long catkins and each silvery hair will grow into a stamen and produce a little bit of pollen to drop in the wind to find a female Pussy Willow flower.
If you pick these and have them in water remember that Willow twigs make a lot of rooting hormone, so if you want to take a cutting of some other plant and put it in water with your Willow twigs the Willow rooting hormone will inspire the other cuttings to put out healthy roots.
I live with a Lilac Tip Siamese Cat named Twm whose silver toes are just like Pussy Willows.