There is only one species or type of lettuce. Its scientific name is Lactuca sativa. It grows best in mild weather. High heat can kept lettuce from growing to this full size and can make the leaves taste bitter.
The lettuce requirement had shifted from the iceberg type grown in the open field to the romaine and leafy lettuces that needed greenhouse or rain shelters for production.
The technology of rain shelter gives high harvest recovery at lower costs, and yields a highly differentiated product in terms of product safety because less agrochemical inputs are used.
Lettuce for fast food