Caltha leptosepala is a species of flowering perennials in the Buttercup family found in western North America from New Mexico to Alaska. Caltha leptosepala is a perennial plant whose leaves start at the base of the stem. The leaves are 13 to 15 cm long and slightly toothed at the edge. The inflorescence has one or more flowers. Each flower is 1 to 4 cm long and is white or sometimes yellow. They have no petals, but these are replaced by petal-like sepals.