An old king had three daughters. He went to town and promised to bring each what she wished. The oldest asked for a green dress, the next for a red dress, and the youngest, whom the king loved better than the others, a white dress.
When he returned he pinned a white rose on the green dress and asked the oldest how much she loved him. She said “more than life.” The second got her dress by responding “more than words.” The youngest said “I love you like meat loves salt.”
When questioned what that meant she replied that she loved him as much as duty will allow. The king became angry and locked her in a tower on the prairie. The Duke of England rides by, sees her there, climbs up, rescues her, and takes her to England as his bride.
The other daughters marry too. The king gets old and lonesome and goes to live with the eldest. She scorns him, and he goes to his next daughter. She puts him in the stable to sleep. Meanwhile the husbands wage war on England.
The youngest girl and the duke come over and find the king wandering around crazy with honeysuckle vines for a crown. They care for him and find the elder sisters stuck in a thornbush. Their husbands put them there. ‘Good enough for ye!’ says the old king.
The duke wins the war and takes the king back to England. The youngest serves a meal without salt. The king complains. Then she brings him a dish of salt and just stands there. He understands and gets his senses back. He sends his servant across the water to fetch the white dress and a whole bough of white roses, fresh as the day they were picked. The king gives them to his daughter.
Sources: Ten variants of the tale – “Love Like Salt”: http://www.pitt.edu/~dash/salt.html ‘Grandfather Tales,’ by Richard Chase