LETTUCE (OF. letu.ce, kiitue, Hue, Fr. laituc, from Lat. lartuea, lettuce. from lac, milk), Lactuca. A genus of plants belonging to the natural order Compositor. The garden lettuce (Lactu-ca scariola or Lactuca saliva) is supposed to be a native of the East Indies, but is not known to exist anywhere in a wild state. From remote antiquity it has been cultivated in Europe as an esculent, and particularly as a salad. It has a leafy stem, oblong leaves, a spreading. flat topped panicle, somewhat resembling a eorymb, with yellow flowers, and a fruit without margin. It is now generally cultivated in all parts of the world where the climate admits of it. The many varieties are divided into two groups: cos (or romaine) and cabbage lettuce, the former having the leaves more oblong and upright, requiring to he tied together for blanching; the latter with rounded leaves, which spread out near the ground. Lettuce is generally eaten raw, with
vinegar and oil, more rarely as a boiled vege table. When grown in gardens the seed is planted in rich, loose soil as early in the spring as the ground can be worked. Market garden ers grow the seedling plants in the green house or hot-bed and transplant 8-12 inches apart in the open field after the plants have been well hardened oil% The forcing of lettuce in green houses has been an important industry in the vicinity of large cities in the Northern and Eastern United States. The other species of this genus exhibit nothing of the bland quality of the garden lettuce. The strong-scented lettuce (Lactuca virosa) is distinguished by the prickly keel of the leaves and by a black, smooth seed, with a rather broad margin.