Rhubarb

October 11th, 2007

Alternate Names: Rheum palmatum, Chinese rhubarb, turkey rhubarb

Description: Rhubarb is a perennial plant that grows from thick short rhizomes, comprising the genus Rheum. This genus is in the family Polygonaceae, along with dock, sorrel, knotweeds, knotgrasses and buckwheat. The large, somewhat triangular leaf blades are elevated on long, fleshy petioles. The flowers are small, greenish-white, and borne in large compound leafy inflorescences.

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…..Rhubarb ………………Rhubarb flower…..Rhubarb displayed at grocery

Cultivation and use :
The plant is indigenous to Asia, and many suggest that it was often used by the Mongolians; particularly, the Tatars tribes of the Gobi. The plant has grown wild along the banks of the Volga for centuries; it may have been brought there by Eurasian tribes, such as the Scythians, Huns, Magyars or Mongols. Varieties of rhubarb have a long history as medicinal plants in traditional Chinese medicine, but the use of rhubarb as food is a relatively recent innovation, first recorded in 17th century England, after affordable sugar became available to common people.

Rhubarb is now grown in many areas, primarily for its fleshy petioles, commonly known as rhubarb sticks or stalks. In temperate climates rhubarb is one of the first food plants to be ready for harvest, usually in mid to late Spring (April/May in the Northern Hemisphere, October/November in the Southern). The petioles can be cooked in a variety of ways. Stewed, they yield a tart sauce that can be eaten with sugar and other stewed fruit or used as filling for pies (see rhubarb pie), tarts, and crumbles. This common use led to the slang term for rhubarb, “pie plant”. In Germany, this slang term is also used; the common name being Rhabarber in German. Cooked with strawberries as a sweetener, rhubarb makes excellent jam. It can also be used to make wine. Recently, it has been used in sandwiches.

Rhubarb is actually a herb, but is often used in food as a fruit. In the United States until the 1940s it was considered a vegetable. It was reclassified as a fruit when US customs officials, baffled by the foreign food, decided it should be classified according to the way it was eaten.

In former days, a common and affordable sweet for children in parts of the United Kingdom and Sweden was a tender stick of rhubarb, dipped in sugar. In the UK the first rhubarb of the year is grown by candlelight in dark sheds dotted around the noted “Rhubarb Triangle” of Wakefield, Leeds and Morley.

A homemade rhubarb pieIn warm climates, rhubarb will grow all year round, but in colder climates the parts of the plant above the ground disappear completely during winter, and begin to grow again from the root in early spring. It can be forced, that is, encouraged to grow early, by raising the local temperature. This is commonly done by placing an upturned bucket over the shoots as they come up.

Species
The plant is represented by about 60 extant species. Among species found in the wild, those most commonly used in cooking are the Garden Rhubarb (R. rhabarbarum) and R. rhaponticum, which, though a true rhubarb, bears the common name False Rhubarb. The many varieties of cultivated rhubarb more usually grown for eating are recognised as Rheum x hybridum in the Royal Horticultural Societies list of recognised plant names. The drug rheum is prepared from the rhizomes and roots of another species, R. officinale or Medicinal Rhubarb. This species is also native to Asia, as is the Turkey Rhubarb (R. palmatum). Another species, the Sikkim Rhubarb (R. nobile), is limited to the Himalayas.

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Rheum species have been recorded as larval food plants for some Lepidoptera species including Brown-tail, Buff Ermine, Cabbage Moth, Large Yellow Underwing, The Nutmeg, Setaceous Hebrew Character and Turnip Moth.

Rhubarb History

Watch Your Garden Grow - Rhubarb

Rhubarb: The World’s Favorite Pie Plant

Medicinal Uses:Rhubarb is used as a strong laxative and for its astringent effect on the mucous membranes of the mouth and the nasal cavity.

Rhub is mainly used forConstipation & stool softness

Rhubarb root is used in traditional Chinese medicine as a laxative. Rhubarb contains powerful laxative compounds called anthraquinones, which irritate the colon and stimulate bowel movements.

Rhubarb root also contains tannins, which are believed to reduce inflammation in the colon. Small amounts of rhubarb are used in traditional Chinese medicine for diarrhea due to the tannin content.

Dosage Information:
Rhubarb can be found as capsules, liquid extracts, and dried root.

Bowel movements usually occur 6 to 12 hours after taking rhubarb.

This type of rhubarb (rheum palmatum) should not be confused with common rhubarb.

Side Effects and Safety
Rhubarb should not be used long-term for constipation.

Pregnant or nursing women should not use rhubarb. Children should not use rhubarb.

Rhubarb or other anthraquinone-containing herbs should not be used by people diverticular disease, ulcerative colitis, Crohn’s disease, severe hemorrhoids, blood vessel disease, congestive heart failure, heart disease, severe anemia, abdominal hernia, gastrointestinal cancer, recent colon surgery, or liver and kidney disease.

Rhubarb may interact with drugs called cardiac glycosides, such as digitalis and digoxin (Lanoxin).

Rhubarb may cause harmless discoloration of urine.

Side effects of rhubarb may include strong cramping in the abdomen (due to muscle contractions, electrolyte imbalance (loss of potassium) and loss of body fluids, and dark pigmentation in the colon, called melanosis coli with longer term use. Call your doctor if you experience bloody diarrhea or prolonged abdominal pain after using rhubarb.

Long-term use of anthraquinones has been linked to the development of colorectal growths (adenomas) and cancer.

Large doses of anthraquinones may cause bloody diarrhea or vomiting.

Toxic effects:
Rhubarb leaves contain poisonous substances. Rhubarb leaves contain oxalic acid, a corrosive and nephrotoxic acid that is abundantly present in many plants. The LD50 (median lethal dose) for pure oxalic acid is predicted to be about 375 mg/kg body weight, or about 25 g for a 65 kg (~140 lb) human. While the oxalic acid content of rhubarb leaves can vary, a typical value is about 0.5%, so a rather unlikely five kilograms of the extremely sour leaves would have to be consumed to reach an LD50 dose of oxalic acid. However, the leaves are believed to also contain an additional, unidentified toxin. In the petioles, the amount of oxalic acid is much lower, especially when harvested before mid-June (in the northern hemisphere), but it is still enough to cause slightly rough teeth.

The roots and stems are rich in anthraquinones, such as emodin and rhein. These substances are cathartic and laxative, which explains the sporadic abuse of Rhubarb as a slimming agent. Anthraquinones are yellow or orange and may colour the urine.

Click to see :-> 1. Rhubarb, Turkey 2. Rhubarb, English 3. Rhubarb, Monk’s and also See:-> DOCKS.

Disclaimer:
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.

Resource: http://en.wikipedia.org/wiki/Rhubarb and http://altmedicine.about.com/od/completeazindex/a/rhubarb.htm

1 Comment(s)

Pingback by www.cellulitediary.info » Rhubarb on October 12, 2007 12:14 pm
[...] Mukul wrote a fantastic post today on “Rhubarb”Here’s ONLY a quick extractThe LD50 (median lethal dose) for pure oxalic acid is predicted to be about 375 mg/kg body weight, or about 25 g for a 65 kg (~140 lb) human. While the oxalic acid content of rhubarb leaves can vary, a typical value is about 0.5%, … [...]

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