Botanical name: Sagittaria lancifolia
Common name: Bulltongue Arrowhead
Family: Alismataceae
Origin: Southeastern United States
USDA Plant Hardiness Zone Map
The plant is conspicuous for its large, lance-shaped leaves which grow up from underground rhizomes and its showy, white three-petaled flowers which form at the end of long, thick stalks. The plant likes to grow in fresh or brackish water and is commonly found in ditches, marshes, swamps and along the shores of lakes and streams.
Similar plants: Sagittaria lancifolia (Bulltongue Arrowhead)
Link to this plant:
https://toptropicals.com/catalog/uid/sagittaria_lancifolia.htm