Geum Calthifolium

Bright yellow flowers open on multi-branching stems above thick leathery (presumably caltha or "kingcup" like) leaves which are differently shaped depending on where they grow on the plant, the upper ones being lobed and blunt-toothed, while the lower leaves kidney or rounded heart-shaped and coarsely toothed. This unusual hardy plant is from N.W. North America and is completely new to us.