Marsh Marigold (Caltha palustris) at Bag Pool

"One of the most ancient native plants, probably surviving the glaciations and flourishing after the last retreat of ice, in a landscape inundated by glacial melt waters. Until about 200 years ago, before extensive drainage of the landscape, the Marsh Marigold must have been the most conspicuous plant of early Spring."

Flora Britannica, Richard Mabey (1996)