Lettuce (Lactuca sativa) is an annual leaf vegetable of the aster family (Asteraceae), originated in the Middle East. Lettuce is generally a rich source of vitamins K and A, though the nutritional quality varies, depending on the variety.                                                                      

Lettuce yields can reach up to 50-70 tons/hectare, depending on the species, the number of growth cycles, and soil conditions. It is usually harvested before the flowering phase, as the bolting of the flower stalk elongates the lettuce head, reduces the leaves' size, and imparts a bitter flavor to the crop.                                                                                                                    

The lettuce plant is best suited to a moderate climate, with temperatures of 13-16 °C (temperatures of 7-24 °C for germination). Short days are ideal for growing lettuce. Days lasting longer than 12 hours cause the lettuce to bloom. Lettuce's growth period may last 60-90 days in the autumn and 21-30 days during the summer.