 Lactuca sativa is a member of the Lactuca ( lettuce ) genus and the Asteraceae ( sunflower or aster ) family . The species was first described in 1753 by Carl Linnaeus in the second volume of his Species Plantarum . Synonyms for L. sativa include Lactuca scariola var. sativa , L. scariola var. <unk> and L. scariola var. integrifolia . L. scariola is itself a synonym for L. serriola , the common wild or prickly lettuce . L. sativa also has many identified taxonomic groups , subspecies and varieties , which delineate the various cultivar groups of domesticated lettuce . Lettuce is closely related to several Lactuca species from southwest Asia ; the closest relationship is to L. serriola , an aggressive weed common in temperate and subtropical zones in much of the world . 
