Yellow watercress is a leafy green vegetable that adds a crisp and peppery flavor to salads and sandwiches. It is also a good source of vitamin C, calcium and iron. There are various synonyms for yellow watercress, including garden cress, peppergrass, and nasturtium. Garden cress is the most commonly used synonym, as it is a close relative to yellow watercress and has a similar taste and texture. Peppergrass is another synonym that refers to the spicy flavor of this leafy green. Nasturtium, on the other hand, refers to the flowers of the plant, which are often used in salads and as a garnish.