Romance Lettuce ( Selada)

The lettuce plant has a very short stem initially ( a rosette growth habit) , but when it gradually blooms, the stem and branches lengthen and produce many flower heads that look like those of dandelions, but smaller. This is referred to as bolting. When grown to eat, lettuce is harvested before it bolts. Lettuce is used as a food plant by the larvae of some Lepidoptera. Lettuce ( Lactuca sativa) is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important as the leaf. Both the English name and the Latin name of the genus are ultimately derived from lac, the Latin word for “ milk, ” referring to the plant’ s milky juice. Mild in flavour, it has been described over the centuries as a cooling counterbalance to other ingredients in a salad. Chinese lettuce ( L. sativa var. asparagina) types generally have long, sword-shaped, non-head-forming leaves, grown in night soil with a bitter and robust flavor unlike Western types, for use in stir-fried dishes and stews. They are divided into “ stem-use” types ( called celtuce in English) , and “ leaf-use” types such as youmaicai ( Chinese: ¹ ¥ Ü ; pinyin: yó umà icà i) or shengcai (  Ü /   Ü ) , respectively. Romaine ( L. sativa var. romana) , also called Cos, grows in a long head of sturdy leaves with a firm rib down the center. Unlike most lettuces, it is tolerant of heat. Some lettuces ( especially iceberg) have been specifically bred to remove the bitterness from their leaves. These lettuces have high water content and so are less " nutritionally dense" than are the more bitter lettuces and those with darker leaves. While all lettuces contain antioxidants and vitamin K, romaine and looseleaf lettuce contain five to six times the vitamin C and five to ten times the vitamin A of iceberg. Romaine and butterhead lettuce are good sources of folate. Lettuce naturally absorbs and concentrates lithium