Photo taken 29/07/10 at Woodwalton Fen, Cambs.
This flowers between July and September. As the name suggests, it can either grow in fresh water (as in the photos) or on land (usually on waste ground, banks near water or arable).
Photo taken 29/07/10 at Woodwalton Fen, Cambs.
Photo taken 15/08/11 on the Grand Union Canal, near Milton Keynes, Bucks.