Laitue is bib or butterhead lettuce, which is sometimes called (laitue pommée). ‘Laitue’ is also a general term for lettuce as well but you tend to see salade used more often as the generic term. Other varieties of lettuce, such as batavia, romaine or feuille de chêne are sold by their name.
It was one of the vegetables Charlemagne recommended for the gardens in his empire.
Image by Dwight Sipler