ABSTRACT
The species was first described in 1753 by Carl Linnaeus in the second volume of his Species Plantarum. Lettuce is native to the Mediterranean region, and it was first cultivated by the ancient Egyptians in around 4,500 B.C., who turned it from a weed, whose seeds were used to produce oil, into a plant grown for its leaves. Lettuce is one of the most important vegetable crops of temperate regions and is also widely cultivated in tropical as well as subtropical regions of the world. Lettuce is a good source of vitamin A, vitamin K and potassium, as well as a minor source for several other minerals and vitamins. The content of nutrients is highest in the dark green outer leaves but it is low in calorie. Lettuce plant is a lactiferous herb. Plants generally have a height of 15 to 30 cm. The leaves are colourful, mainly in green and red colour spectrums, with some variegated varieties.
