Pecan

Extensive cultivation and naturalization have confounded interpretation of the natural range of Carya illinoinensis . The pecan hybridizes with C . aquatica ( C . × lecontei Little [= Hicoria texana Le Conte]), C . cordiformis ( C . × brownii Sargent), C . laciniosa ( C . × nussbaumeri Sargent), and C . ovata , and reputedly with the tetraploid C . tomentosa ( C . × schneckii Sargent). J. W. Thieret (1961) pointed out that C . illinoinensis was the spelling Wangenheim used throughout his publication, and there is no valid basis for accepting the deviant spelling " illinoensis " that is so widely used today (E. L. Little Jr. 1979).

Carya illinoinensis is the state tree of Texas.

Native Americans used Carya illlinoinensis medicinally as a dermatological aid and as a remedy for tuberculosis (D. E. Moerman 1986).

Grown extensively in China for its edible nuts.

Trees , to 44 m. Bark light gray or brownish, ridged with appressed scales or exfoliating with small platelike scales. Twigs tan to reddish brown, slender, hirsute, conspicuously scaly, sometimes becoming glabrous. Terminal buds yellowish brown, oblong, 6-12 mm, hirsute, scaly; bud scales valvate; axillary buds protected by bracteoles fused into hood. Leaves 4-7 dm; petiole 4-8 cm, glabrous to scurfy with short single hairs or scattered fascicles. Leaflets (7-)9-13(-17), lateral petiolules 0-7 mm, terminal petiolules 5-25 mm; blades ovate-lanceolate, often falcate, 2-16 × 1-7 cm, margins finely to coarsely serrate, without tufts of hairs, apex acuminate; surfaces abaxially hirsute or with scattered unicellular and 2-rayed fasciculate hairs, scaly with large peltate scales and small round peltate scales, adaxially without hairs or rarely hirsute with unicellular hairs along midrib, and with scattered 2-6-rayed fasciculate hairs, moderately scaly in spring. Staminate catkins essentially sessile, to 18 cm, stalks with small capitate-glandular trichomes; anthers sparsely pilose. Fruits dark brown, ovoid-ellipsoid, not compressed, 2.5-6 × 1.5-3 cm; husks rough, 3-4 mm thick, dehiscing to base or nearly so, sutures winged; nuts tan to brown and mottled with black patches, ovoid-ellipsoid, not compressed, not angled, smooth; shells thin. Seeds sweet. 2 n = 32.

Trees to 50 m tall. Terminal buds with 4 or more false-valved scales, yellowish brown. Leaves 25-35 cm; petiole 4-8 cm, glabrous or glabrescent; rachis generally glabrous or glabrescent; leaflets (7 or)9-13(-17), lateral ones shortly petiolulate or sessile, blade ovate-lanceolate to elliptic-lanceolate or long elliptic, 7-18 × 2.5-4 cm, with scattered, peltate scales, abaxially pubescent or glabrescent, base oblique, broadly cuneate or subrounded, apex acuminate; terminal petiolule 5-25 mm. Male spikes 8-14 cm; peduncle nearly absent. Anthers sparsely pilose. Nuts ovoid-ellipsoid, 3-5 × 2-3 cm; husk without prominent wings; shell without longitudinal ridges, ca. 1 mm thick, 2-chambered at base, lacunae present. Fl. May, fr. Sep-Nov. 2n = 32, rarely 64.

Ark., Ill., Ind., Iowa, Kans., Ky., La., Miss., Mo., Okla., Tenn., Tex.; Mexico.

Flowering spring.

Along stream banks, river flood plains, and on well-drained soils; 0-600(-1000)m.

Cultivated. Fujian, Hebei, Henan, Hunan, Jiangsu, Jiangxi [native to United States]

Juglans illinoinensis Wangenheim, Beytr. Teut. Forstwiss., 54, plate 18, fig. 43. 1787, excluding fruit; Hicoria olivaeformis (Michaux) Nuttall; H. pecan (Marshall) Britton

Juglans illinoinensis Wangenheim, Beytr. Teut. Forstwiss. 54. 1787; Hicoria olivaeformis (Michaux) Nuttall; H. pecan (Marshall) Britton; Juglans olivaeformis Michaux; J. pecan Marshall.

pecan
pecan hickory
sweet pecan
Illinois nut
soft-shelled hickory

More info for the term: cover

Pecan provides cover for a variety of birds and mammals in the
oak-hickory forests of southeastern United States [10].

More info for the term: tree

Pecan is a long-lived, medium to large, native, deciduous tree ranging
from 100 to 150 feet (30-45 m) in height and 6 to 7 feet (1.8-2.1 m) in
diameter [5]. The gray trunk is shallowly furrowed and flat-ridged with
ascending branches forming an irregular, rounded crown. The twigs are
gray brown and hairy when young but become rough and furrowed on mature
trees. Flowers are borne in staminate and pistillate catkins.
Staminate catkins are in threes and bear small green flowers;
seed-bearing flowers occur singly or a few at the end of new growth.
The leaves are narrow, pointed, and curved at the tip with tooth margins
yellow-green above and paler below. The nut is brown, cylindric,
thin-shelled, and enveloped in a four-winged husk [7,9].

Pecan grows principally in the bottomlands of the Mississippi River
valley. Its range extends westard from southern Indiana through
Illinois, southeastern Iowa, and eastern Kansas, south to central Texas,
and eastward to western Mississippi and western Tennessee. Pecan occurs
locally in southwestern Ohio, Kentucky, Alabama, and central Mexico.
Its best commercial development is on river-front lands of the
Mississippi Delta and along major rivers west of the Delta to Texas
[2,18]. Pecan is cultivated in Hawaii [25].

More info for the term: fire regime

Pecan is susceptible to fire damage at all ages because of the low
insulating capacity of the bark [18,24].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

Periodic fires in late spring and early summer effectively controlled
pecan growth in the Mississippi River Basin, killing most of the
seedling reproduction [24].

More info on this topic.

More info for the term: phanerophyte

Phanerophyte

More info for the terms: cover, tree, vines

Pecan is most common on well-drained loamy soils not subjected to
prolonged flooding. Throughout its range it is largely limited to
bottom alluvial soils of relatively recent origin. Its best development
is on riverfront ridges and well-drained flats [18]. It rarely grows on
low and poorly drained clay flats; it is usually replaced by water
hickory (Carya aquatica) on these sites [1].

In addition to the species listed in the SAF cover types, common tree
associates of pecan include slippery elm (Ulmus rubra), sugarberry
(Celtis laevigata), box elder (Acer negundo), silver maple (A.
saccharinum), roughleaf dogwood (Cornus drummondii), and swamp-privet
(Forestiera acuminata). Common understory components include pawpaw
(Asimina triloba), giant cane (Arundinaria gigantea), and pokeweed
(Phytolacca americana). Vines often present are poison-ivy
(Toxicodendron radicans), grape (Vitis spp.), Alabama supplejack
(Berchemia scandens), greenbriers (Smilax spp.), and Japanese
honeysuckle (Lonicera japonica) [4,17,18].

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the terms: hardwood, swamp

40 Post oak - blackjack oak
61 River birch - sycamore
63 Cottonwood
65 Pin oak - sweetgum
73 Southern redcedar
75 Shortleaf pine
76 Shortleaf pine - oak
78 Virginia pine - oak
79 Virginia pine
80 Loblolly pine - shortleaf
81 Loblolly pine
82 Loblolly pine - hardwood
83 Longleaf pine - slash pine
88 Willow oak - water oak - diamondleaf oak
89 Live oak
91 Swamp chestnut oak - cherrybark oak
92 Sweetgum - willow oak
93 Sugarberry - American elm - green ash
94 Sycamore - sweetgum - American elm
95 Black willow
96 Overcup oak - water hickory
101 Baldcypress - tupelo
103 Water tupelo - swamp tupelo

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES12 Longleaf - slash pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory
FRES16 Oak - gum - cypress
FRES17 Elm - ash - cottonwood

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: forest

K089 Black Belt
K100 Oak - hickory forest
K101 Elm - ash forest
K111 Oak - hickory - pine forest
K112 Southern mixed forest
K113 Southern floodplain forest

Light fires will kill the tops of small pecan trees and saplings. Heavy
burns may kill trees 10 to 12 inches (25-30 cm) d.b.h. and wound others,
providing entries for serious butt-rotting fungi. Particularly hot
fires may kill mature pecan trees [18].

Pecan nuts are eaten by a number of bird species, fox and gray
squirrels, opposums, racoons, and peccaries [10,18]. White-tailed deer
sometimes heavily browse older pecan trees [19].

More info for the term: tree

Tree

More info for the term: seed

Pecan seedling establishment is difficult due to small mammals pilfering
seed and girdling seedlings [24]. A number of small insects attack
pecan but rarely become epidemic [18].

AL AR IL HI IN IA KS KY LA MS
MO OH OK TN TX MEXICO

Pecan is widely planted as an ornamental, and for its sweet edible nuts.
The nuts have a high percentage of fat and are used extensively in
candies and cookies [20]. The leaves and bark are sometimes used as an
astringent [23].

More info on this topic.

Pecan flowers from March to May about a week after the leaves have
started to open. The nuts mature from September to October; seedfall
begins in September and ends in December [2,11].

Pecan will sprout from the stump after aboveground portions are killed
by fire [18,24].

More info for the terms: caudex, root crown, seed

survivor species; on-site surviving root crown or caudex
off-site colonizer; seed carried by animals or water; postfire yr 1&2

More info for the terms: competition, seed, tree

Seed production and dissemination: Seed production starts when the
trees are about 20 years old, but optimum seed-bearing age is 75 to 225
years. The trees bear fair to good crops almost every year. A mature
tree yields about 100 pounds (40 kg) of nuts per year. The seed is
disseminated by water, squirrels, and birds [12,18].

Seedling development: Under normal conditions, pecan nuts remain
dormant until germination starts in early April. Exceptionally dry
weather or heavy competition greatly reduces seedling survival. Under
favorable condition, pecan seedlings grow 3 feet (0.9 m) per year after
they have been established for several years [18].

Vegetative reproduction: Small stumps and fire-girdled seedlings and
saplings sprout very rapidly. Horticultural varieties of pecan are
propagated by budding and stem grafting [18].

More info on this topic.

Pecan is classified as shade intolerant but is more shade tolerant than
cottonwood or willow. It responds well to release in all age groups,
provided that the trees have good vigor. Pecan is a subclimax species
[11,18].

Carya illinoensis (Wangenh.) K. Koch [18]

The currently accepted scientific name for pecan is Carya illinoinensis
(Wangenh.) K. Koch [14]. There are no recognized subspecies, varieties,
or forms. Pecan hybrid products are [23]:

Carya illinoinensis x C. aquatica = C. X lecontei Little
Carya illinoinensis x C. laciniosa = C. X nussbaumeri Sarg.
Carya illinoinensis x C. tomentosa = C. X schnecki Sarg.
Carya illinoinensis x C. cordiformis = C. X brownii Sarg.

Pecan has been successfully planted on surface-mined lands of Indiana,
Oklahoma, and Missouri [3]. The deep, lateral roots can provide
excellent watershed protection [24].

More info for the term: fuel

Pecan wood is inferior to that of other hickories and is not important
commercially. It is occasionally used for furniture, flooring,
agricultural implements, tool handles, and fuel [21,23].

Medium to large tree to 50 m. Leaflets 11-17, acuminate, serrate. Fruits up to 8 cm, oblong, smooth, brown, thin-shelled.

A rare and uncertain escape

USA southwards to Mexico