Although the name suggests that this plant is restricted to Wales, this is not actually the case. Western Poppy would, perhaps, be the more appropriate name for it. Its natural range extends from Yorkshire, southwards through Wales and Somerset to Devon and Cornwall. Its favourite haunts are beside rivulets, moist and shady rocky places.
Flowering from June to AugustThe Observer’s Book of Wild Flowers, compiled by W. J. Stokoe (1957)