These hardy perennials are natives of Europe and America. They belong to the Buttercup family, Ranunculaceae. These plants are found growing in marshes and by the banks of streams. Caltha palustris, King Cup or Marsh Marigold, forms clumps of kidney-shaped, glossy, dark green leaves, which grow up to 4 inches across and have serrated edges. The cup-shaped, bright golden yellow flowers grow up to 1½ inches across and have a waxy appearance. They are borne in long-stalked clusters in the spring. This plant grows up to 2 feet high with a spread of 18 inches.

Grow Calthas in full sun, in wet ground by a pond, in a bog garden, or in shallow water up to 5 inches deep.

They can be divided in the fall or early spring, or fresh seeds may be sown in the fall.

Caltha palustris;
Caltha polypetala;
Caltha biflora;
Caltha leptosepala.