Pacific Silverweed

Basal leaves grow 1-2′ tall with silvery undersides. Stalks with a single, cheerful yellow flower. Rapidly spreads via stolons, colonizing moist soils, including beaches. Common on the Pacific coast in North America. Sun or part shade. Deciduous. Traditionally used for its edible root.

Hardy to zone 5

H. Zell, CC BY-SA 3.0, via Wikimedia Commons