Tapegrass, Eelgrass, or Wild Celery (Vallisneria americana Michaux): A Native Aquatic and Wetland Plant

Seagrasses are flowering vascular plants that live completely submerged in shallow oceanic and estuarine waters. [NALT]

Species of embryophytes living in marine coastal waters. Flowering plants (angiosperms) that colonised the sea. They are the only flowering plants that can live under seawater and are not related to seaweeds. [AGROVOC]