Photo taken 29/07/10 at Woodwalton Fen, Cambs.
This flowers between July and September, and is found in reed-beds beside tidal rivers, ditches and fens. It can grow up to 10 feet tall, and some that I saw at Woodwalton Fen was certainly over seven foot high.
This shot shows what the leaves look like - photo taken 29/07/10 at Woodwalton Fen, Cambs.