World Library  
Flag as Inappropriate
Email this Article

Pyrus

Article Id: WHEBN0025196680
Reproduction Date:

Title: Pyrus  
Author: World Heritage Encyclopedia
Language: English
Subject: Amygdaloideae, Rust (fungus), List of trees of Canada, Scarce Swallowtail, Saturnia pavonia, Large Tortoiseshell, Antheraea polyphemus, Shipova, Idaho State Arboretum, Fell Arboretum
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Pyrus

"Pyrus" redirects here. For other uses, see Pyrus (disambiguation).
For other uses, see Pear (disambiguation).
Pears
European Pear branch with fruit
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Rosales
Family: Rosaceae
Subfamily: Amygdaloideae[1]
Tribe: Maleae
Subtribe: Malinae
Genus: Pyrus
L.
Species

About 30 species; see text.

The pear is any of several tree and shrub species of genus Pyrus /ˈprəs/, in the family Rosaceae. It is also the name of the pomaceous fruit of these trees. Several species of pear are valued for their edible fruit, while others are cultivated as ornamental trees. The genus Pyrus is classified in subtribe Pyrinae within tribe Pyreae.

Etymology

The English word “pear” is probably from Common West Germanic pera, probably a loanword of Vulgar Latin pira, the plural of pirum, akin to Greek ἄπιος apios (from Mycenaean ápisos),[2] which is of Semitic origin (Aramaic/Syriac "pirâ", meaning "fruit", from the verb "pra", meaning "to beget, multiply, bear fruit"). The place name Perry and Pharisoulopol can indicate the historical presence of pear trees. The term "pyriform" is sometimes used to describe something which is pear-shaped.

Description


The pear is native to coastal and mildly temperate regions of the Old World, from western Europe and north Africa east right across Asia. It is a medium-sized tree, reaching 10–17 m tall, often with a tall, narrow crown; a few species are shrubby.

The leaves are alternately arranged, simple, 2–12 cm long, glossy green on some species, densely silvery-hairy in some others; leaf shape varies from broad oval to narrow lanceolate. Most pears are deciduous, but one or two species in southeast Asia are evergreen. Most are cold-hardy, withstanding temperatures between −25 °C and −40 °C in winter, except for the evergreen species, which only tolerate temperatures down to about −15 °C.

The flowers are white, rarely tinted yellow or pink, 2–4 cm diameter, and have five petals.[3] Like that of the related apple, the pear fruit is a pome, in most wild species 1–4 cm diameter, but in some cultivated forms up to 18 cm long and 8 cm broad; the shape varies in most species from oblate or globose, to the classic pyriform 'pear-shape' of the European pear with an elongated basal portion and a bulbous end.

The fruit is composed of the receptacle or upper end of the flower-stalk (the so-called calyx tube) greatly dilated. Enclosed within its cellular flesh is the true fruit: five cartilaginous carpels, known colloquially as the "core". From the upper rim of the receptacle are given off the five sepals, the five petals, and the very numerous stamens.

Pears and apples cannot always be distinguished by the form of the fruit; some pears look very much like some apples, e.g. the Nashi pear. One major difference is that the flesh of pear fruit contains stone cells (also called "grit").

History

The cultivation of the pear in cool temperate climates extends to the remotest antiquity, and there is evidence of its use as a food since prehistoric times. Many traces of it have been found in the Swiss lake-dwellings. The word “pear”, or its equivalent, occurs in all the Celtic languages, while in Slavic and other dialects, differing appellations, still referring to the same thing, are found—a diversity and multiplicity of nomenclature which led Alphonse de Candolle to infer a very ancient cultivation of the tree from the shores of the Caspian to those of the Atlantic.

The pear was also cultivated by the Romans, who ate the fruits raw or cooked, just like apples.[4] Pliny's Natural History recommended stewing them with honey and noted three dozen varieties. The Roman cookbook attributed to Apicius, De re coquinaria, has a recipe for a spiced, stewed-pear patina, or soufflé.[5]

A certain race of pears, with white down on the under surface of their leaves, is supposed to have originated from P. nivalis, and their fruit is chiefly used in France in the manufacture of perry (see also cider). Other small-fruited pears, distinguished by their early ripening and apple-like fruit, may be referred to as P. cordata, a species found wild in western France and southwestern England. Pears have been cultivated in China for approximately 3000 years.

The genus is thought to have originated in present-day western China in the foothills of the Tian Shan, a mountain range of Central Asia, and to have spread to the north and south along mountain chains, evolving into a diverse group of over 20 widely recognized primary species . The enormous number of varieties of the cultivated European pear (Pyrus communis subsp. communis), are without doubt derived from one or two wild subspecies (P. communis subsp. pyraster and P. communis subsp. caucasica), widely distributed throughout Europe, and sometimes forming part of the natural vegetation of the forests. Court accounts of Henry III of England record pears shipped from La Rochelle-Normande and presented to the King by the Sheriffs of the City of London. The French names of pears grown in English medieval gardens suggest that their reputation, at the least, was French; a favored variety in the accounts was named for Saint Rule or Regul', Bishop of Senlis.[6]

Asian species with medium to large edible fruit include P. pyrifolia, P. ussuriensis, P. × bretschneideri, P. × sinkiangensis, and P. pashia. Other small-fruited species are frequently used as rootstocks for the cultivated forms.

Major recognized taxa


  • Pyrus amygdaliformis—Almond-leaved pear
  • Pyrus armeniacifolia—Apricot-leaved pear
  • Pyrus boissieriana
  • Pyrus bourgaeana—Iberian pear
  • Pyrus × bretschneideri—Chinese white pear; also classified as a subspecies of Pyrus pyrifolia
  • Pyrus calleryana—Callery pear
  • Pyrus communis – European pear
  • Pyrus cordata—Plymouth pear
  • Pyrus cossonii—Algerian pear
  • Pyrus dimorphophylla
  • Pyrus elaeagnifolia—Oleaster-leaved pear
  • Pyrus fauriei
  • Pyrus gharbiana
  • Pyrus glabra
  • Pyrus hondoensis
  • Pyrus koehnei—Evergreen pear of southern China and Taiwan
  • Pyrus korshinskyi
  • Pyrus mamorensis
  • Pyrus nivalis—Snow pear
  • Pyrus pashia—Afghan pear
  • Pyrus ×phaeocarpa
  • Pyrus pseudopashia
  • Pyrus pyrifolia—Nashi pear, Sha Li; tree species native to China, Japan, and Korea, also known as the Asian pear
  • Pyrus regelii
  • Pyrus salicifolia—Willow-leaved pear
  • Pyrus × serrulata
  • Pyrus × sinkiangensis—thought to be an interspecific hybrid between P. ×bretschneideri and Pyrus communis
  • Pyrus syriaca—Syrian pear
  • Pyrus ussuriensis—Siberian pear
  • Pyrus xerophila

Cultivation


According to Pear Bureau Northwest, about 3000 known varieties of pears are grown worldwide. [7] The pear is frequently raised by sowing the pips (seeds) of ordinary cultivated or of wild kinds, these forming what are known as free or pear stocks, on which the choicer varieties are grafted for increase. Both quince and clonally produced pear rootstocks are also used for Pyrus communis orchards. For new varieties the flowers can be cross-bred to preserve or combine desirable traits. The fruit of the pear is produced on spurs, which appear on shoots more than one year old.

Three species account for the vast majority of edible fruit production, the European pear Pyrus communis subsp. communis cultivated mainly in Europe and North America, the Chinese white pear (bai li) Pyrus ×bretschneideri, and the Nashi pear Pyrus pyrifolia (also known as Asian pear or apple pear), both grown mainly in eastern Asia. There are thousands of cultivars of these three species. A species grown in western China, P. sinkiangensis, and P. pashia, grown in southern China and south Asia, are also produced to a lesser degree.

Other species are used as rootstocks for European and Asian pears and as ornamental trees. The Siberian pear, Pyrus ussuriensis (which produces unpalatable fruit) has been crossed with Pyrus communis to breed hardier pear cultivars. The Bradford pear (Pyrus calleryana 'Bradford') in particular has become widespread in North America, and is used only as an ornamental tree, as well as a blight-resistant rootstock for Pyrus communis fruit orchards. The Willow-leaved pear (Pyrus salicifolia) is grown for its attractive, slender, densely silvery-hairy leaves.

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-

  • 'Beth'[8]
  • 'Concorde'[9]
  • 'Conference'[10]      
  • 'Joséphine de Malines'[11]      
  • 'Louise Bonne of Jersey'[12]
  • 'Onward'[13]
  • 'Williams' Bon Chrétien'[14]

Harvest

Summer and autumn cultivars of Pyrus communis, being climacteric fruits, are gathered before they are fully ripe, while they are still green, but snap off when lifted. In the case of the 'Passe Crassane', long the favored winter pear in France, the crop is traditionally gathered at three different times: the first a fortnight or more before it is ripe, the second a week or ten days after that, and the third when fully ripe. The first gathering will come into eating last, and thus the season of the fruit may be considerably prolonged.

Nashi pears are allowed to ripen on the tree.

Diseases and pests

Production

Top ten pear producers
(in thousand metric tons)
Rank Country 2009 2010 2011
1  China 14,416,430 15,231,858 15,945,013
2  Italy 872,368 736,646 926,542
3  United States 868,357 738,085 876,086
4  Argentina 700,000 704,242 691,270
5  Spain 463,969 476,686 502,234
6  Turkey 384,244 380,003 386,382
7  South Africa 340,088 368,495 350,527
8  Netherlands 295,000 274,000 336,000
9  India 308,487 336,049 334,774
10  Japan 351,500 284,900 312,800
World 20,888,647 22,731,087 22,511,100
Source: UN Food & Agriculture Organization [15]

Storage

Pears may be stored at room temperature until ripe.[16] Pears are ripe when the flesh around the stem gives to gentle pressure.[16] Ripe pears are optimally stored refrigerated, uncovered in a single layer, where they have a shelf life of 2 to 3 days.[16]

Uses

Pears are consumed fresh, canned, as juice, and dried. The juice can also be used in jellies and jams, usually in combination with other fruits or berries. Fermented pear juice is called perry or pear cider.

Pears ripen at room temperature. They will ripen faster if placed next to bananas in a fruit bowl.[17] Refrigeration will slow further ripening. Pear Bureau Northwest offers tips on ripening and judging ripeness: Although the skin on Bartlett pears changes from green to yellow as they ripen, most varieties show little color change as they ripen. Because pears ripen from the inside out, the best way to judge ripeness is to "Check the Neck": apply gentle thumb pressure to the neck or stem end of the pear. If it yields to gentle pressure, then the pear is ripe, sweet, and juicy. If it is firm, leave the pear at room temperature and Check the Neck daily for ripeness.[18]

The culinary or cooking pear is green but dry and hard, and only edible after several hours of cooking. Two Dutch cultivars are "Gieser Wildeman" (a sweet variety) and "Saint Remy" (slightly sour).[19]

Pear wood is one of the preferred materials in the manufacture of high-quality woodwind instruments and furniture. It is also used for wood carving, and as a firewood to produce aromatic smoke for smoking meat or tobacco. Pear wood is valued for kitchen spoons, scoops and stirrers, as it does not contaminate food with color, flavor or smell, and resists warping and splintering despite repeated soaking and drying cycles. Lincoln[20] describes it as "a fairly tough, very stable wood... (used for) carving... brushbacks, umbrella handles, measuring instruments such as set squares and T-squares... recorders... violin and guitar fingerboards and piano keys... decorative veneering." Pearwood is the favored wood for architect's rulers because it does not warp. It is similar to the wood of its relative, the apple tree, Pyrus malus (also called Malus domestica) and used for many of the same purposes.[20]

Pear leaves were smoked in Europe before tobacco was introduced.[21][22]

Health benefits

Pears, raw
Nutritional value per 100 g (3.5 oz)
Energy 239 kJ (57 kcal)
Carbohydrates 15.23 g
- Sugars 9.75 g
- Dietary fiber 3.1 g
Fat 0.14 g
Protein 0.36 g
Thiamine (vit. B1) 0.012 mg (1%)
Riboflavin (vit. B2) 0.026 mg (2%)
Niacin (vit. B3) 0.161 mg (1%)
Pantothenic acid (B5) 0.049 mg (1%)
Vitamin B6 0.029 mg (2%)
Folate (vit. B9) 7 μg (2%)
Choline 5.1 mg (1%)
Vitamin C 4.3 mg (5%)
Vitamin E 0.12 mg (1%)
Vitamin K 4.4 μg (4%)
Calcium 9 mg (1%)
Iron 0.18 mg (1%)
Magnesium 7 mg (2%)
Manganese 0.048 mg (2%)
Phosphorus 12 mg (2%)
Potassium 116 mg (2%)
Sodium 1 mg (0%)
Zinc 0.1 mg (1%)
USDA Nutrient Database

Pears are a good source of dietary fiber and a good source of vitamin C. Most of the vitamin C, as well as the dietary fiber, is contained within the skin of the fruit.[23]

Pears are less allergenic than many other fruits, and pear juice is therefore sometimes used as the first juice introduced to infants.[24] However, caution is recommended for all fruit juice consumption by infants, as studies have suggested a link between excessive fruit juice consumption and reduced nutrient intake, as well as a tendency towards obesity.[25] Pears are low in salicylates and benzoates, so are recommended in exclusion diets for allergy sufferers.[26] Along with lamb and rice, pears may form part of the strictest exclusion diet for allergy sufferers.[27]

Most of the fiber is insoluble, making pears a good laxative.[28]

Herbalism

In ancient Greece, pears were used to treat nausea.

Cultural references

Pears grow in the sublime orchard of Alcinous, in Odyssey vii: "Therein grow trees, tall and luxuriant, pears and pomegranates and apple-trees with their bright fruit, and sweet figs, and luxuriant olives. Of these the fruit perishes not nor fails in winter or in summer, but lasts throughout the year."

'A Partridge in a Pear Tree' is the first gift in "The Twelve Days of Christmas" cumulative song, this verse is repeated twelve times in the song.

See also

References

External links

  • California Pear Recipes – Over one hundred pear recipes from California Pears.
  • European pear varieties – description of Australian commercial pears
  • Fruit in mythology – Symbolism of pears
  • Handbook of Practical Gardening – Gardening information on pears.
  • "The Pear in History, Literature, Popular Culture, and Art"
  • Pear Panache – a collection of pear recipes for chefs and by chefs
  • Pear Recipes – collection of pear recipes from Pear Bureau Northwest
  • Pear Varieties – Information about pear varieties grown in California.
  • University of Georgia Pear Page – History of cultivation and commerce.
  • Morton Arboretum specimens
  • When to pick and how to ripen pears to perfection; Oregon State University Extension Service; July 2009
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.