Silverweed (Argentina pacifica or Potentilla anserina subsp. pacifica) is a common garden weed in the Pacific Northwest. It has an edible and reasonably tasty root. The only problem is that good-sized roots are barely bite sized. Still, it is a native plant with some potential for domestication. You might look at the roots when you pull these plants for any that have promise.
I pulled this one today and saved it because the root is not bad: