Early spring greens and buds of "Caltha palustris" are edible when cooked. "Caltha palustris" is a very variable species. "Caltha palustris" is a highly variable species. "Caltha palustris" is infertile when self-pollinated. In North America "Caltha palustris" is sometimes known as cowslip. In "Caltha palustris" up to two hundred seeds may be produced by each flower.