'Popweed'

Don't really know what this plant is called but I've always called it 'Popweed '. It's always found growing near water and it has an abundance of lovely shades of pink flowers. After its finished flowering it has these pods that get bigger before popping and releasing seeds for next year's plants.
The fun part is searching for a big bulbous pod and then if you touch it, it pops and the seeds explode out, making you jump in surprise.