 Lettuce was first cultivated in ancient Egypt for the production of oil from its seeds . This plant was probably selectively bred by the Egyptians into a plant grown for its edible leaves , with evidence of its cultivation appearing as early as <unk> BC . Lettuce was considered a sacred plant of the reproduction god Min , and it was carried during his festivals and placed near his images . The plant was thought to help the god " perform the sexual act <unk> . " Its use in religious ceremonies resulted in the creation of many images in tombs and wall paintings . The cultivated variety appears to have been about 30 inches ( 76 cm ) tall and resembled a large version of the modern romaine lettuce . These upright lettuces were developed by the Egyptians and passed to the Greeks , who in turn shared them with the Romans . Circa 50 AD , Roman agriculturalist Columella described several lettuce varieties – some of which may have been ancestors of today 's lettuces . 
