Pontederia cordata, pickerel weed

pickerel weed
Pontederia cordata

Hardiness: Zones 3 to 10
Plant type: Herbaceous perennial                                                                  Height: 2- 4'
Spread: 1.5- 2'
Sun: Full sun
Water: Wet
Bloom time: June to October
Bloom color: Purple
Soil: Muddy pond margins, or rich loam when grown in containers.

Notes: Used in wetland restoration, pickerel weed attracts pollinators, and its dense clumps of stems and leaves provide shelter and shade for fish. 

More information on this plant here.