I saw this plant in a swamp in central Maine, USA. I think it is a type of wild hyacinth. Are there domesticated versions? Anyone know how to grow one in a large planter pond?
The spear shaped leaves belong to the plant.
This must be Purple Pickerelweed, Pontaderia cordata.
I've made lots of water 'ponds' but I would invest in great water lilies. I would probably try growing this guy but there is just so much room even in the largest pots. Water lilies shade the water so that the fish I've added don't boil.