This rhizomatous perennial is marginally aquatic and has upright foliage that forms a clump. It has bluish-green lanced-shaped leaves on long stalks and the purple tube-shaped flowers appear in a cluster above the foliage on a tall scape during summer. 

Hardiness zones 8 to 11 

Thalia dealbata is naturally found south-eastern North America from Florida to Mississippi down to eastern Texas growing in rich, humus wet soils. It prefers warm climates in an open sunny position and though tolerates light frosts it dies back and re-shooting during spring.

Water Canna is grown for its attractive foliage and tropical effect and is planted in bog gardens or around ponds and along watercourses. It may also be grown in containers then placed in ponds establishing from division in one season. ID 1074

Note:
The plant spreads quickly by rhizomes and may become a weed problem.

Thalia (THAL-ee-ah) dealbata (day-al-BAHT-ah)

Marantaceae (MAR-an-TAY-see-ee)
Arrowroot