Lettuce

Country of origin: South Korea
Plant: Sang-chu (Lettuce)

Lettuce (Lactuca sativa) is an annual plant of the aster or sunflower family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce was first cultivated by the ancient Egyptians who turned it from a weed, whose seeds were used to produce oil, into a plant grown for its leaves. Lettuce spread to the Greeks and Romans, the latter of whom gave it the name “lactuca”, from which the English “lettuce” is ultimately derived.
Generally grown as a hardy annual, lettuce is easily cultivated, although it requires relatively low temperatures to prevent it from flowering quickly. It can be plagued with numerous nutrient deficiencies, as well as insect and mammal pests and fungal and bacterial diseases. L. sativa crosses easily within the species and with some other species within the Lactuca genus; although this trait can be a problem to home gardeners who attempt to save seeds, biologists have used it to broaden the gene pool of cultivated lettuce varieties.