watercress

mat-forming perennial found in cold springs of the eastern United States

perennial Eurasian cress growing chiefly in springs or running water having fleshy pungent leaves used in salads or as a potherb or garnish; introduced in North America and elsewhere

annual or biennial cress growing in damp places sometimes used in salads or as a potherb; troublesome weed in some localities

perennial herb found on streams and riversides throughout Europe except extreme north and Mediterranean; sometimes placed in genus Nasturtium