pecan

Pecan
Carya illinoinensis Morton Arboretum acc. 1082-39*3
Conservation status
Secure
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Fagales
Family:	Juglandaceae
Genus:	Carya
Species:	C. illinoinensis
Binomial name
Carya illinoinensis (Wangenh.) K.Koch

The pecan [IPA:piːˌkɑn] (Carya illinoinensis or illinoensis) is a species of hickory, native to south-central North America, in Mexico from Coahuila south to Jalisco and Veracruz,^[1][2] in the United States from southern Iowa, Illinois and Indiana east to western Kentucky, North Carolina, South Carolina and western Tennessee, south through Georgia, Alabama, Mississippi, Louisiana, Texas, Oklahoma and Arkansas

"Pecan" is from an Algonquian word, meaning a nut requiring a stone to crack.^[3] It is pronounced in various parts of the US as pi-KAHN, pi-KAN, or PEE-kan.

Growth

Ripe pecan nuts on tree

The pecan tree is a large deciduous tree, growing to 20–40 m (66–130 ft) in height, rarely to 44 m (140 ft);^[2] taller trees to 50–55 m (160–180 ft) have been claimed but not verified. It typically has a spread of 12–23 m (39–75 ft) with a trunk up to 2 m (6.6 ft) diameter. A 10-year-old sapling will stand about 5 m (16 ft) tall. The leaves are alternate, 30–45 cm (12–18 in) long, and pinnate with 9–17 leaflets, each leaflet 5–12 cm (2.0–4.7 in) long and 2–6 cm (0.79–2.4 in) broad. The flowers are wind-pollinated, and monoecious, with staminate and pistillate catkins on the same tree; the male catkins are pendulous, up to 18 cm (7.1 in) long; the female catkins are small, with three to six flowers clustered together.

Male catkins in spring

The fruit is an oval to oblong nut, 2.6–6 cm (1.0–2.4 in) long and 1.5–3 cm (0.59–1.2 in) broad. The nut itself is dark brown with a rough husk 3–4 mm (0.12–0.16 in) thick that starts out green and turns brown at maturity, at which time it splits off in four sections to release the thin-shelled nut.^[2][4][5][6] Pecans, like the fruit of all other members of the hickory genus, are not true nuts but technically a drupe (fruit with a single stone or pit). The husks are produced from the exocarp tissue of the flower while the part known as the nut develops from the endocarp.

The nuts of the pecan are edible, with a rich, buttery flavor. They can be eaten fresh or used in cooking, particularly in sweet desserts but also in some savory dishes. One of the most common desserts with the pecan as a central ingredient is the pecan pie, a traditional southern U.S. recipe. Pecans are also a major ingredient in praline candy, most often associated with New Orleans.^[7]

In addition to the pecan nut, the wood is also used in making furniture, in wood flooring, as well as flavoring fuel for smoking meats.

Cultivation

Pecans with and without shells

A large pecan tree in downtown Abilene, Texas.

Pecans were one of the most recently domesticated major crops. Although wild pecans were well-known among the colonial Americans as a delicacy, the commercial growing of pecans in the United States did not begin until the 1880s.^[8] Today, the U.S. produces between 80% and 95% of the world's pecans, with an annual crop of 150–200 thousand tons.^[9] The nut harvest for growers is typically around mid-October. Historically, the leading pecan-producing state in the U.S. has been Georgia, followed by Texas, New Mexico and Oklahoma; they are also grown in Arizona, South Carolina and Hawaii. Outside the United States, pecans are grown in Australia, Brazil, China, Israel, Mexico, Peru and South Africa. They can be grown approximately from USDA hardiness zones 5 to 9, provided summers are also hot and humid.

Pecan trees may live and bear edible nuts for more than three hundred years. They are mostly self-incompatible, because most cultivars, being clones derived from wild trees, show incomplete dichogamy. Generally, two or more trees of different cultivars must be present to pollenize each other.

Choosing cultivars can be a complex practice, based on the Alternate Bearing Index and their period of pollinating. Commercial planters are most concerned with the Alternate Bearing Index, which describes a cultivar's likelihood to bear on an alternating years (index of 1.0 signifies highest likelihood of bearing little to nothing every other year).^[10] The period of pollination groups all cultivars into 2 families: those which shed pollen before they are able to receive pollen (protandrous) and those which shed pollen after becoming receptive to pollen (protogynous)^[11]. Planting cultivars from both families within 250 feet is recommended for proper pollination.

Diseases

Nutrition

Pecans are a good source of protein and unsaturated fats. Like walnuts (which pecans resemble), pecans are rich in omega-6 fatty acids, although pecans contain about half as much omega-6 as walnuts. Pecans contain much less omega-3 fatty acid than walnuts.^{[12] [13]}

A diet rich in nuts can lower the risk of gallstones in women.^[14] The antioxidants and plant sterols found in pecans reduce high cholesterol by reducing the "bad" LDL cholesterol levels.^[15]

Clinical research published in the Journal of Nutrition (September 2001) found that eating about a handful of pecans each day may help lower cholesterol levels similar to what is often seen with cholesterol-lowering medications.^[16] Research conducted at the University of Georgia has also confirmed that pecans contain plant sterols, which are known for their cholesterol-lowering ability.^[17]

The U.S. Food and Drug Administration (FDA) has acknowledged this and related research and approved the following qualified health claim: "Scientific evidence suggests, but does not prove, that eating 1.5 ounces per day of most nuts, such as pecans, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease."^[18]

History

Pecans first became known to Europeans in the 16th century; the Spanish explorer Álvar Núñez Cabeza de Vaca saw and wrote first about this plant.^{[citation needed]} The Spaniards brought the pecan into Europe, Asia, and Africa beginning in the 16th century. In 1792 William Bartram reported in his botanical book, Travels, a nut tree, "Juglans exalata' that some botanists today argue was the American pecan tree, but others argue was hickory, "Carya ovata"^[19]. Pecan trees are native to the United States, and writing about the pecan tree goes back to the nation founders. Thomas Jefferson planted pecan trees, "Carya illinoinensis,' (Illinois nuts) in his nut orchard at his beautiful home, Monticello, in Virginia. George Washington reported in his journal that Thomas Jefferson gave him "Illinois nuts" pecans which grew at Mount Vernon, Virginia, George Washington's home.

Symbolism

In 1919 the 36th Texas Legislature made the pecan tree the state tree of Texas. In southeast Texas, the Texas Pecan Festival is celebrated every year. In 1906 then Texas Governor James Stephen Hogg asked that a pecan tree be planted at his grave instead of a traditional headstone, requesting that the nuts be distributed throughout the state to make Texas a "Land of Trees".^[9]

See also

• Southern Pecan beer; a beer that uses the pecan nut.

Food portal

References

External links

Wikimedia Commons has media related to: Carya illinoinensis

• National Pecan Shellers Association
• Carya illinoinensis images at bioimages.vanderbilt.edu
• National Center for Home Food Preservation — Home Preservation of pecans
• USDA Forest Service: Carya illinoensis