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Scientific Name: Juglands nigra
Author: Kwon, Sam Soonchae
Common Names: "black walnut"
Higher taxa: *According to the Cronquist System of Classification
(Jones, 1986)
Division MAGNOLIOPHYTA
Class MAGNOLIOPSIDA (dicots)
Subclass Hamamelidae
Order Juglandales
Family Juglandaceae
Genus Juglands
Species
nigra
Identification:
1. J. nigra L., Black Walnut. Pith light brown. Leaflets 9-19,
lanceolate or ovate, 3-15 cm long, 1.5 - 5.5 cm wide, pubescent beneath,
acuminate, serrate, base rounded, oblique, or cordate, sessile or subsessile;
petioles 6.5-14 cm long; rachis and petiole glandular pubescent. Fruit
globose, glabrous, usually 4-5 cm in diameter. (Radford,363)
Dendrology: Leaves: alternate, pinnately compound, upto 19 leaflets. Buds: gray, pubescent, essentially naked. Twigs: pith chambered, leaf scar lacking hairy fringe. Bark: dark brown with deep narrow furrows and thin interlacing ridges, chocolate brown color when scraped. Fruit: globose nut, husk smooth, shell corrugations rounded. Most valuable timeber species in the U.S. Odor of nut, bark and branches strong. (Heywood, 569)
Authority and Reference: Carl Linnaeus , Species Plantarium (Hooker,)
Location described: London: Herbarium, The Linnean Society of London, Burlinton House, Piccadilly, London, WIV OLQ, England, Great Britain (Type: not known)(Hooker,)
GENERAL DISTRIBUTION :
Black walnut is found throughout the eastern United States.
It grows as far north as southern Minnesota, southern Wisconsin, southern
Michigan, and southern Ontario. Isolated populations occur in the southern
half of New York, Vermont, western Massachusetts, and northwestern Connecticut.
Its range extends south to northwestern Florida, and to Mississippi, Arkansas,
and Louisiana except for the Mississippi Valley and Delta regions. In the
Midwest, isolated populations occur in eastern Texas, western Oklahoma,
central Kansas, and southeastern South Dakota" (www. dept of agriculture).
Juglands nigra L. |
||
AREA | STATUS | REFERENCES |
North America: Continental United States; Canada |
Yes | Duncan & Duncan, 1988 |
Eastern North America: United States east of Mississippi |
Yes | Duncan & Duncan, 1988 |
Southeastern United States: AL AR DE DC FL GA KY MD NC SC TN VA WV |
Yes | Duncan & Duncan, 1988 |
Southern Appalachian States: AL GA KY MD NC SC TN VA WV |
Yes | Duncan & Duncan, 1988 |
Coastal Plain | Yes | Duncan & Kartesz,1981 |
Piedmont | Yes | Duncan & Kartesz,1981 |
Blue Ridge Mountains | Yes | Duncan & Kartesz,1981 |
Ridge and Valley | Yes | Duncan & Kartesz,1981 |
Cumberland Plateau | Yes | Duncan & Kartesz,1981 |
Georgia | Yes | Duncan & Kartesz,1981 |
Clarke County, Georgia | Yes | Jones, |
Sams Farm | ||
|
Yes | Sam Kwon, Pers. Ob. |
|
? | - |
|
No | Sam Kwon, Pers. Ob. |
|
No | Sam Kwon, Pers. Ob. |
REGENERATION PROCESSES :
Seed production: Black walnut produces abundant seed crops irregularly,
perhaps twice in 5 years. Although open-grown trees produce seed as early
as 8 years after planting, the minimum seed-bearing age for commercial
quantities of seed is about 12 years. Best seed production begins when
the tree is about 30 years old and continues for another 100 years .
Dispersal: Black walnut seed is heavy. The seeds are dispersed by squirrels carrying seed from beneath the tree and burying them at a distance .
Seedling development: Many black walnut seedlings germinate from the nuts cached by squirrels in the fall. Normal freezing and thawing usually causes the seeds to break dormancy the following spring, but germination is often delayed, sometimes until the second year .
Vegetative reproduction: Small black walnut trees usually sprout from the stump when they are cut or killed back by fire. Shoots originating high on the older stumps often decay, but shoots from the root crown generally are free from defect" (www. dept of agriculture)
SITE CHARACTERISTICS :
Black walnut is found on a variety of sites but grows best on
deep, well-drained neutral soils that are moist and fertile . It grows
slowly on wet bottomlands, dry ridges, and slopes. Black walnut is common
on limestone soils and grows extremely well on deep loams and fertile alluvial
deposits. Good agricultural soils are generally favorable sites for black
walnut. In the Appalachians, the best wlanut trees are found on bottomlands
and coves below 4,000 feet (1,200 m) .
Principal associates are identified in the Distribution and Occurrence frame. Other common tree associates include American elm (Ulmus americana), hackberry (Celtis laevigata), green ash (Fraxinus pennsylvanica), box elder (Acer negundo), and butternut (Juglans cinerea)" (www. dept of agriculture)
SUCCESSIONAL STATUS :
Black walnut is classified as shade intolerant. In mixed forest
stands, it must be dominant to survive, although it can survive in the
relatively light shade of black locust . Black walnut is found in many
of the climax associations but because of its intolerance is not classified
as a climax tree in the strict sense. In general, black walnut maintains
itself in most stands as scattered single trees occupying openings in the
canopy(www. dept of agriculture) .
SEASONAL DEVELOPMENT :
Black walnut normally begins flowering about mid-April in the
southern part of its geographic range and mid-June in the northern part
of its range. The fruit ripens in September or October of the same year,
dropping shortly after the leaves fall "(www. dept of agriculture)
.
How to Encounter:
To locate Juglands nigra, travel to Sam's farm. This is located on Hwy
78 towards Lexington, on the left right past mile marker 16. Then on the
old field and it can be found in the northeast direction from the entrance,
near the creek. You will not find this species in the 1 hector plot.
References:
Duncan, W.H. & Marion B Duncan.
1988. Trees of the Southeastern United States. The University of Georgia
Press. Ahens, GA. (ISBN 0-8203-0954-0). pages 63-64.
Duncan, W. H. & J.T. Kartesz. 1981.
Vascular Flora of Georgia. The University of Georgia Press. Athens, GA.
(ISBN 0-8203-0538-3). pages 47.
Heywood, V.H. Flowereing Plants of the World. Mayflower Book Inc., New
York. pages 569.
Hooker, J. D. & D Jackson. Index Kewensis. Clerendon Press, Oxford
University
Jones, S.B. Checklist of the Vascular Flora
of Clarke County, Georgia. Dept. of Botany, University of Georgia. Athens,
GA. page 12.
Jones, S. B. & A.E. Luchsinger. 1986. Plant Systemics. Dept. of Botany,
University of Georgia. Athens, Ga. (ISBN 0-07-032796-3). pages 319.
Kwon, S. 1997. Personal observations of the species taken at Sam's Farms.. University of Georgia. Athens, Ga.
Radford, A.E. , H.E. Ahles & C.R. Bell. 1968. Manual of
the Vasular Flora of the Carolinas. University of North Carolina Press.
Chapel Hill, NC.
www. The United States Department of Agriculture. (could not
find again on internet for direct address)
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