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Lettuce

2007 Schools Wikipedia Selection. Related subjects: Food and agriculture;
Plants

                          iLettuce
   Iceberg lettuce field in Northern Santa Barbara County
   Iceberg lettuce field in Northern Santa Barbara County
                 Scientific classification

   Kingdom:  Plantae
   Division: Magnoliophyta
   Class:    Magnoliopsida
   Order:    Asterales
   Family:   Asteraceae
   Genus:    Lactuca
   Species:  L. sativa

                                Binomial name

   Lactuca sativa
   L.
        Lettuce (butterhead)
   Nutritional value per 100 g
       Energy 10 kcal   60 kJ

   Carbohydrates            2.2 g
   - Dietary fibre  1.1 g
   Fat                      0.2 g
   Protein                  1.4 g
   Water                    96 g
   Vitamin A  166 μg        18%
   Folate (Vit. B9)  73 μg  18%
   Vitamin C  4 mg          7%
   Iron  1.2 mg             10%
   Percentages are relative to US
   recommendations for adults.
   Source: USDA Nutrient database

   Lettuce is a temperate annual or biennial plant most often grown as a
   leaf vegetable. In Western countries, it is typically eaten cold and
   raw, in salads, hamburgers, tacos, and several other dishes. In some
   places, including China, lettuce is typically eaten cooked and use of
   the stem are as important as use of the leaf.

   The Lettuce plant has a short stem initially (a rosette growth habit),
   but when it blooms, the stem lengthens and branches, and it produces
   many flower heads that look like those of dandelions, but smaller. This
   is called bolting. When grown to eat, lettuce is harvested before it
   bolts.

   Lettuce is used as a food plant by the larvae of some Lepidoptera - see
   list of Lepidoptera which feed on lettuces.

History

   The wild predecessor of our modern lettuce, Lactuca serriola, can still
   be seen all over Europe and the more temperate parts of Asia. It is
   likely that it originated on the Mediterranean rim on rocky wasteland
   or woodland clearings. This ancient wild relative of the modern lettuce
   contains lactucarium, a narcotic similar to opium. The Romans took
   advantage of this property by eating lettuce at the end of a meal to
   induce sleep.

   In earlier times the Egyptians held a similar view of the lettuce.
   However as well as a hypnotic or an aid to sleep, the plant was also
   linked with male virility. As any vegetable gardener will know the
   lettuce can bolt or surge vertically upwards. This combined with a
   milky substance they can exude when cut could have been seen as a
   symbol of the male phallus ejaculating . It is thought these Egyptian
   plants were closely linked with the modern day Cos lettuce and could
   have originated on the Turkish coast opposite the island of Kos.

   With the vast number of lettuce cultivars in existence, it is near
   impossible to pin-point their exact origins. Certainly both the Roman
   and Egyptian lettuce continued to be eaten long after the two great
   civilizations started to decline. Many may have hybridised with the
   wild type serriola to make the modern sativa.

   It is certain that these ancient civilizations saw the plant as both an
   appetite stimulant and an aid to sleep. In ancient Greece this led to
   confusion whether to eat the plant at the beginning or the end of a
   meal. The physician Galen, from Pergamon, would eat the plant to allow
   restful sleep and allow him to study without 'mental churnings' the
   following day. Somewhat contrary to this, a century earlier, Rufus of
   Ephesos declared the opposite; claiming lettuce 'fogged the memory and
   prevented clear thought'.

   One of the earliest records of the modern European lettuce was in a
   piece by Lucas van Valkenborch who showed clear depictions of modern
   butterhead lettuces in his piece 'Allegory of Summer'.

Cultivars

   Some lettuce cultivars
   Enlarge
   Some lettuce cultivars

   There are six commonly recognised Cultivar Groups of lettuce which are
   ordered here by head formation and leaf structure; there are hundreds
   of cultivars of lettuce selected for leaf shape and colour, as well as
   extended field and shelf life, within each of these Cultivar Groups:
     * Butterhead, also called Boston or Bibb forms loose heads; it has a
       buttery texture. Butterhead cultivars are most popular in Europe.
     * Chinese lettuce types generally have long, sword-shaped,
       non-head-forming leaves, with a bitter and robust flavour unlike
       Western types, appropriate for use in stir-fried dishes and stews.
       Chinese lettuce cultivars are divided into "stem-use" types (called
       celtuce in English), and "leaf-use" types such as youmaicai
       (Chinese: 油麦菜; pinyin: yóumàicài) or shengcai (生菜).
     * Crisphead, also called Iceberg, which form tight, dense heads that
       resemble cabbage. They are generally the mildest of the lettuces,
       valued more for their crunchy texture than for flavour. Cultivars
       of iceberg lettuce are the most familiar lettuces in the USA. The
       name Iceberg comes from the way the lettuce was transported in the
       US starting in the 1920s on train-wagons covered in crushed ice,
       making them look like icebergs.
     * Looseleaf, with tender, delicate, and mildly flavoured leaves.
     * Romaine, also called Cos, is a head-forming type with elongated
       leaves.
     * Summer Crisp, also called Batavian, which form moderately dense
       heads with a crunchy texture; this type is intermediate between
       iceberg and looseleaf types.

   Some lettuces (especially iceberg) have been specifically bred to
   remove the bitterness from their leaves. These lettuces have a high
   water content with very little nutrient value. The more bitter lettuces
   and the ones with pigmented leaves contain antioxidants.

   Rocket, also known as arugula, garden rocket, rocket salad, rugola, or
   roquette[1], is a type of leaf vegetable, and although often mistaken
   for a sort of lettuce, is in fact an herb, being a member of the
   mustard family.

Trivia

   More lettuce cultivars
   Enlarge
   More lettuce cultivars
     * The largest lettuce head was one that weighed 11 kg (25 lb), of the
       Salad Bowl cultivar, grown by Colin Bowcock of Willaston, England,
       in 1974.

     * In the United States, 95% of all head lettuce is grown in
       California and Arizona.

     * On Saturday Night Live
          + The October 3, 1998 episode (Season 24, Episode 2) of the
            television comedy show featured a fake commercial for "KCF
            Shredders", a hypothetical fast food lettuce meal for hip hop
            Americans. (KCF was a jab at KFC.)
          + The December 3, 2005 episode of Saturday Night Live featured a
            digital short touting lettuce "through good times and bad".
     * Lactucarium (or "Lettuce Opium") is a mild opiate-like substance
       that is contained in all types of lettuce.
     * Yazidis consider eating lettuce taboo. See Taboo food and drink.

   Retrieved from " http://en.wikipedia.org/wiki/Lettuce"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
