XIV ̳ - ADVANCED TECHNOLOGIES OF SCIENCE AND EDUCATION (19-21.04.2018)

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. . Subclass Caryophyllidae Order - Polygonales , Family Polygonaceae - the Buckwheat Family

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"Subclass Caryophyllidaerder - Polygonales, Family Polygonaceae - the Buckwheat Family"

Diversity:A family of 43 genera and about 1100 species of herbs (mostly),some shrubs and (rarely) trees.The ethnoflora includes,rhubarb(Rheum rhaponicum), a plant grown for its petioles,buckwheat(Fagopyrum esculentum).

Distribution:Mostly centered in Northern and temperate parts of the World. TheTexas floraincludes 8 genera, 69 species and 22 infraspecific taxa.

Floral structure: CA(5) CO(0) A(5-8) G(3)

CA(3+3) CO(0) A(3+3) G(3)

Significant features: Most species of this family, with the exception of the large genusEriogonum(false buckwheat) show a unique vegetative feature at the node. A modified stipule encloses the node for form a sheathing structure known as anocrea. The nodes (like theCaryophyllaceae subclass ) tend to beswollenand this feature is signaled by the Genus namePolygonumwhich translates to 'many kneed', a reference to the swollen nodes.The flowers are small, perfect (usually) and either show a bi- or uniseriate calyx that often continues to develop after anthesis (accrescent) to produce a winged enclosure for the fruit,atrigonal(three-sided) orlenticular(lens shaped) achene.

Buckwheat is a variety of plants in thedicotfamilyPolygonaceae: the Eurasian genusFagopyrum, the North American genus Eriogonum, and the Northern Hemisphere genusFallopia. Either of the latter two may be referred to as "wild buckwheat." Despite the name, buckwheats are not related to wheat, as they are notcereals/grasses(familyPoaceae) instead, buckwheat is related tosorrels,knotweeds,andrhubarb.

Fagopyrum-The crop plant, common buckwheat, is Fagopyrum esculentum.Tartary buckwheat(F. tataricumGaertn.) or "bitter buckwheat" is also used as a crop, but it is much less common. Despite the common name and the grain-like use of the crop, buckwheat is not a cereal orgrass. The grain is called apseudocerealto emphasize that the plant is not related towheat.Buckwheat plants grow quickly, beginning to produce seed in about 6 weeks and ripening at 10 to 11 weeks. They grow 30 to 50 inches (75 to 125cm) tall. This genus has five-petaled flowers arranged in a compoundracemethat produces laterally floweredcymoseclusters.WithinFagopyrum, the cultivated species are in the cymosum group, withF. cymosumL. (perennial buckwheat),F. giganteumandF. homotropicum.

Eriogonum-A commonchaparralplant throughout western North America, especially California, where it is the largest genus of dicotsand at least 70 species have been cataloged.The flowers have six petals and occur incymes.

Fallopia-The agricultural weed known as 'wild buckwheat' (Fallopia convolvulus) is in the same family, but not closely related to the crop species.

Etymology:The name 'buckwheat' or 'beech wheat' comes from its triangular seeds, which resemble the much larger seeds of the beech nut from thebeech tree, and the fact that it is used like wheat.

History:The wild ancestor of common buckwheat isF. esculentumssp.ancestrale.F. homotropicumis interfertile withF. esculentumand the wild forms have a common distribution, inYunnan. The wild ancestor of tartary buckwheat isF. tataricumssp.potanini.

Agricultural production:Buckwheat is a short season crop that does well on low-fertility or acidic soils, but the soil must be well drained.Too much fertilizer, especially nitrogen,will reduce yields. In hot climates,it can only be grown by sowing late in the season,so that it will bloom in cooler weather.The presence ofpollinatorsgreatly increases the yield.Buckwheat is sometimes used as agreen manure,plant forerosioncontrol, or as wildlife cover and feed.It is raised for grain where a short season is available, either it is used as a second crop in the season, or because the climate is limiting and can be a reliable cover crop in summer to fit a small slot of warm season for establishment;do that quickly, which suppresses summer weeds.

Present-day production:Common buckwheat is by far the most important species, economically, accounting for over 90% of the world's buckwheat production. World's largest producer now isChina.

Chemical composition:(Seeds)Starch:71-78% ingroats, 70-91% in different types of flour,Starchis 25%amyloseand 75%amylopectin.Depending on hydrothermal treatment, buckwheat groats contain 7-37% of resistant starch.Proteins:Crude protein is 18%, withbiological valuesabove 90% .This can be explained by a high concentration of all essentialamino acids,especiallylysine,threonine,tryptophan, and the sulphur-containing amino acids.Minerals:Rich iniron(60-100 ppm),zinc(20-30 ppm) andselenium(20-50 ppb).Antioxidants:10-200 ppm ofrutinand 0.1-2% oftannins.

Aromatic compounds:Salicylaldehyde(2-hydroxybenzaldehyde) was identified as a characteristic component of buckwheat aroma.2,5-dimethyl-4-hydroxy-3(2H)-furanone,(E,E)-2,4-decadienal,phenylacetaldehyde,2-methoxy-4-vinylphenol,(E)-2-nonenal,decanalandhexanalalso contribute to its aroma. They all haveodour activity valuemore than 50,but the aroma of these substances in an isolated state does not resemble buckwheat.Inositol derivatives:Fagopyritol A1 and fagopyritol B1 (mono-galactosyl D-chiro-inositol isomers), fagopyritol A2 and fagopyritol B2 (di-galactosyl D-chiro-inositol isomers), and fagopyritol B3 (tri-galactosyl D-chiro-inositol). Herb:Antioxidants:1-10%rutinand 1-10%tannins.Fagopyrin:0.4 to 0.6mg/g offagopyrins(at least 3 similar substances).

Food:The fruit is anachene, similar tosunflowerseed, with a single seed inside a hard outer hull. The starchy endosperm is white and makes up most or all of buckwheat flour. The seed coat is green or tan, which darkens flour. The hull is dark brown or black, and some may be included in flour as dark specks. The nectar from flowers make a dark-colored honey.In recent years, buckwheat has been used as a substitute for other grains ingluten-free beer. Although it is not a cereal, it can be used in the same way asbarleyto produce amaltthat can form the basis of amashthat will brew abeerwithoutgliadinorhordein(togethergluten) and therefore can be suitable forcoeliacsor others sensitive to certainglycoproteins.

Medicinal uses:Buckwheat contains aglucosidecalledrutin, amedicinal chemicalthat strengthenscapillarywalls. One clinical study showed mixed results in the treatment ofchronic venous insufficiency.Dried leaves for tea were manufactured in Europe under the brand name "Fagorutin".A protein has been found to bindcholesteroltightly. It is being studied for reducing plasma cholesterol in people withhyperlipidemia, contains noglutenand can consequently be eaten by people withcoeliac diseaseor gluten allergies. Many bread-like preparations have been developed. However,it can be a potent and potentially fatal allergen. In sensitive people, it provokes IgE-mediated anaphylaxis.The cases of anaphylaxis induced by buckwheat ingestion have been reported in Korea, Japan and Europe, where it is more often described as a "hidden allergen".A recent article by Heffler showed allergic reactions, even severe ones, induced by accidental ingestion, are not so rare as previously described.

Upholstery filling:Buckwheat hulls are used as filling for a variety ofupholsteredgoods, includingpillowsandzafu(like a natural help for sleep problems). The hulls are durable and do not conduct or reflect heat as much as synthetic fills. They are sometimes marketed as an alternative natural fill to feathers for those with allergies. However, medical studies to measure the health effects concluded such do contain higher levels of a potential allergen that may trigger asthma in susceptible individuals than do new synthetic ones.

Biological control:It is currently being researched and actively used, as a pollen and nectar source to increase natural enemy numbers to control crop pests in New Zealand.

References:

1. McGraw-Hill Science & Technology Dictionary McGraw-Hill Dictionary of Scientific and Technical Terms. Copyright 2003, 1994, 1989, 1984, 1978, 1976, 1974 by McGraw-Hill Companies, Inc.

2. A Field Guide to Edible Wild Plants: Eastern and central North America (Peterson Field Guides) Lee Allen Peterson (Author, Illustrator, Photographer), Roger Tory Peterson (Editor, Illustrator) Publication Date: September 1, 1999 ;Series:Peterson Field Guides

3. Smithsonian Handbooks: Herbs (Smithsonian Handbooks) Lesley Bremness (Author) Publication Date: October 1, 2002 ;Series: Smithsonian Handbooks

4. The Way of Chinese Herbs Michael Tierra (Author) Publication Date: August 1, 1998 by Pocket Books

5. The Encyclopedia of Medicinal Plants: A Practical Reference Guide to over 550 Key Herbs and Their Medicinal Uses ,Andrew Chevallier (Author), Publication Date: October 1, 1996;Publisher: DK ADULT (October 1, 1996)

6. Word Tutor Copyright 2004-present by eSpindle Learning, a 501(c) nonprofit organization.eSpindle provides personalized spelling and vocabulary tutoring online;

7. Buckwheat Fields and Brush Fencesby Charles G. Stater(Author), Publisher:The Kaleidograph Press; First Edition edition (1935)


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