Buy Watercress at Trees-Plants. Watercress is known for its strong peppery flavor. The Watercress is used in salads due to being very high in vitamin C and minerals. This plant will grow well in very wet soil or even in a tray of water. The Watercress plant can also be grown indoors. This is a very hardy and strong plant. The scientific name for Watercress is Nasturtium officinale.