Short answers, pulled from the story.
Ancient Egyptians grew lettuce for its white, milky latex, which they believed enabled the god Min to perform sexual acts untiringly. This sacred plant, known today as Lactuca sativa, was originally cultivated near the Caucasus region to harvest oil-rich seeds starting in 2680 BC.
Iceberg lettuce was originally developed in 1894 for growth in the northern United States by Burpee Seeds and Plants. It received its name from the way it was transported in crushed ice, where the heads of lettuce looked like icebergs.
In 2023, world production of lettuce and chicory reached 28 million tonnes, with China accounting for 53 percent of the total. The four main types in the Western world are looseleaf, romaine, crisphead, and butterhead, while stem lettuce is widely consumed in China.
Contaminated lettuce is often a source of bacterial, viral, and parasitic outbreaks in humans, including E. coli and Salmonella. The plant's high water content and the fact that it is eaten raw make it particularly vulnerable to food-borne pathogens such as Listeria monocytogenes and viruses including hepatitis A.
Lettuce seeds remain viable for only a few months at room temperature, but when stored cryogenically, this life increases to a half-life of 500 years for vaporized nitrogen and 3,400 years for liquid nitrogen. Seeds keep best when stored in cool conditions at 0 degrees Celsius.