Very pale, butter-yellow (the Swiss call them "butter balls"), semi-double, bowl-shaped flowers bloom from bronzed buds in late spring and early summer. Toothy, lobed, dark green leaves shine below. It's clumping, upright, and compact, and will tolerate somewhat heavy soils. In cooler climes, it can take full sun if watered well.
Mature size: 24 inches tall & 18 inches WMinimum temperature: -30° F