Also known as Mexican marigold, Tagetes tenuifolia wandered south to Central America and Columbia. Corralled and planted into flower gardens up north by 1798, it is still cultivated today for its feathery, citrus-scented mounded foliage studded with masses of tiny lemon-yellow single flowers. Pull a few edible petals and sprinkle on salads to add color and a bit of spicy flavor.