In the pond, the lovely Caltha palustris flore plena is making a welcome appearance. This is the double form of the native Marsh Marigold, with sunny yellow fully double flowers, and smaller shiny green leaves than the single species. I also have the native plant, and the white variety, Caltha palustris alba, both of which are valuable early flowering plants for the spring water garden. Caltha palustris forms wonderful seed pods which give interest in flower arrangements. All these plants grow well in shallow water margins or damp soil in borders.