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Juglans nigra

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(Redirected fromBlack walnut)
"Black walnut" redirects here. For other uses, seeBlack walnut (disambiguation).

Eastern black walnut
Leaves and fruit
Scientific classificationEdit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fagales
Family: Juglandaceae
Genus: Juglans
Section: Juglanssect.Rhysocaryon
Species:
J. nigra
Binomial name
Juglans nigra
Natural range

Juglans nigra,theeastern American black walnut,is aspeciesofdeciduoustreein thewalnutfamily,Juglandaceae,native toNorth America.It grows mostly inriparian zones,from southernOntario,west to southeastSouth Dakota,south toGeorgia,northernFloridaand southwest to centralTexas.Wild trees in the upperOttawa Valleymay be an isolated native population or may have derived from planted trees.

Black walnut is an important tree commercially, as the wood is a deep brown color and easily worked. Walnutseeds(nuts) are cultivated for their distinctive and desirable taste. Walnut trees are grown both for lumber and food, and manycultivarshave been developed for improved quality wood or nuts. Black walnut is susceptible tothousand cankers disease,which provoked a decline of walnut trees in some regions.

Black walnut is anecdotally known for beingallelopathic,which means that it releases chemicals from its roots and other tissues that may harm other organisms and give the tree a competitive advantage. There is not, however, solid scientific consensus that allelopathic chemicals in black walnut are the primary source of its competitive growth in an area.[2]

Description

[edit]
  • OdorMost parts of the tree including leaves, stems, and fruithuskshave a very characteristic pungent or spicy odor. This odor is lacking in the nut itself.[3][4]
  • TrunkHeight 30–40 m (100–130 ft). Under forest competition, it develops a tall and straighttrunk.When grown in an open area it has a short trunk and broad crown.[4]
  • BarkThebarkis typically grey-black and deeply furrowed into thin ridges that gives the bark a diamond shaped pattern.[4]
  • PithThepithof the twigs is chambered and light brown.[3]
  • BudsThebudsare pale silky and covered in downy hairs. The terminal buds are ovate, and8 mm (5⁄16in) long, and slightly longer than broad, the lateral buds are smaller and superposed.[4]
  • LeavesThe leaves are pinnatelycompoundand alternately arranged on the stem. They are 30–60 cm (1–2 ft) long, typicallyeven-pinnatebut there is heavy variation among leaves. The stems have 15–23 leaflets, when terminal leaf is included, with the largest leaflets located in the center,7–10 cm (2+3⁄4–4 in) long and2–3 cm (3⁄4–1+1⁄4in) broad.[4]The leaflets have a rounded base and a long pointed (acuminate) tip as well as having aserratededge.[5]The leaves are overall dark green in color and are typically hairy on the underside.
  • Leaf scarTheleaf scarhas three prominent bundle scars[6]and has a notch on the side that points toward the tip of the branch (distal side)
  • FlowersBlack walnut ismonoecious.Themale(staminate) flowers are in droopingcatkins8–10 cm (3+1⁄4–4 in) long. These are borne from axillary buds on the previous year's growth. Thefemale(pistillate) flowers are terminal, in clusters of two to five on the current year's growth.[7]
  • FruitRipens during the summer/autumn into a spherical fruit (nut) with a brownish-green, semifleshy husk and a brown, corrugated nut. The whole fruit, including the husk, falls in October; the seed is relatively small and very hard.
A young black walnut tree full of fruit inEastern Oklahoma

The fruit production tends to occur irregularly with some years producing larger crops than others (seemast year). Fruiting may begin when the tree is 4–6 years old, but large crops take 20 years. Total lifespan ofJ. nigrais about 130 years. Like other trees of the orderFagales,such as oaks, hickories, chestnuts, and birches, it is monoecious, with wind-pollinated catkins. Male and female flowers are in separatespikes,and the female flowers typically appear before the male on a single tree (dichogamy). As a consequence,self-pollinationis unlikely. However, individual trees are commonly self-compatible; if they are not pollinated by neighboring trees, they may set self-fertilized seeds.[7]For maximum seed germination, the seeds should becold-moist stratifiedfor 3–4 months, although the exact time depends on the seed source.[7]The seedlings emerge in April or May. While most trees with taproots have a reputation for slow growth, black walnut is an exception and can achieve very rapid growth in the seedling stage, typically 90 cm (35 in) their first year and even more in the second year.[7]Black walnut will not leaf out until temperatures have warmed sufficiently. Leafout in spring is initiated when daytime highs reach approximately 70 °F (21 °C) and leaf drop in fall when daytime highs fall below 65 °F (15 °C). As such, the exact timing will vary in different regions of the US and depending on the weather conditions from year to year, leafout is typically early April in the southern part of its range and sometimes not until the end of May or beginning of June in cooler areas. Leaf drop in fall may begin in late September in cooler regions and not until November in southern areas.[7]

Black walnut has a strongtaproot,which makes the seedlings resilient, but difficult to transplant.

Black walnut is more resistant to frost than theEnglishorPersian walnut,but thrives best in the warmer regions of fertile, lowland soils with high water tables, although it will also grow in drier soils, but much more slowly.[4]Some specimens have been found to survive frosts down to −43 °C.[8]Some soils preferred by black walnut includealfisolandentisolsoil types.[7]Black walnut grows best on sandy loam, loam, or silt loam type soils but will also grow well on silty clay loam soils. It prefers these soils because they hold large quantities of water, which the tree draws from during rainless periods.[7]

Visually, black walnut is similar to thebutternut(Juglans cinerea) in leaf shape, and the range also overlaps significantly. The fruits are quite different, and their presence makes an identification easy, as black walnut fruits are round (spherical) and butternuts are more oval-oblong shaped. When a fruit is not available, two species can be differentiated based on theleaf scars,or the place where the leaf meets the stem: butternut has a leaf scar with a flat upper edge and with a velvety ridge above that flat part, but black walnut has an indented leaf scar with no hairy ridge.[9]

Ecology

[edit]

Black walnut is primarily apioneer speciessimilar toredandsilver mapleandblack cherry.Because of this, black walnut is a common weed tree found along roadsides, fields, and forest edges in the eastern US. It will grow in closed forests, but is classified as shade intolerant; this means it requires full sun for optimal growth and nut production.

Black walnut's native range extends across much of the eastern US. It is absent from the coastal plain south ofNorth Carolinaas well as the Mississippi Valley, and does not occur in the northern tier of the eastern US, where the frost-free season is too short for the nuts to develop. Its western range extends all the way to the eastern Great Plains, beyond which climate conditions become too dry for it.

Black walnut is one of the most abundant trees in the eastern US, particularly the Northeast, and its numbers are increasing due to epidemics that have affected other tree species, including emerald ash borer, chestnut blight, butternut canker, wooly hemlock adelgid, dogwood anthracnose, Dutch elm disease, and spongy moth infestations. Widespread clear-cutting of oaks due to spongy moth damage in the 1970s–1980s particularly aided in the tree's spread. The aggressive competitive strategy of black walnut such as its fast growth, alleopathic chemicals, and rodent-dispersed seeds, have also contributed.

Fruits after falling from tree

The nuts are food for many rodents and make up to 10% of the diet ofeastern fox squirrels.[6][10]The nuts are also eaten by species of birds. The leaves are browsed bywhite tailed deer,[10]although they are not a preferred food.

Where the range of the eastern black walnut overlaps that of the Texas black walnut (J. microcarpa), the two species sometimes interbreed, producing populations with characteristics intermediate between the two species.[11]J. nigraandJ. cinereaoften grow in the same range as well but they do not hybridize naturally.[7][10]

The tree's roots often formendomycorrhizalrelationships with fungi in the genusGlomus.Some endomycorrhizal relations improve the plant's growth.[7]

Species often associated withJ. nigraincludeyellow-poplar(Liriodendron tulipifera),white ash(Fraxinus americana),black cherry(Prunus serotina),basswood(Tilia americana),American beech(Fagus grandifolia),sugar maple(Acer saccharum),oaks(Quercusspp.), andhickories(Caryaspp.). Near the western edge of its range, black walnut may be confined to floodplains, where it grows either withAmerican elm(Ulmus americana),common hackberry(Celtis occidentalis),green ash(Fraxinus pennsylvanica), andboxelder(Acer negundo), or with basswood andred oak(Quercus rubra) on lower slopes and other favorable sites.[7]

Cultivation

[edit]

Planting

[edit]
Seed shell cracked open to expose kernel. Under the right conditions, a black walnut tree will sprout and grow from a seed like the one pictured here.[12]

While its primary native region is the Midwest and east-central United States, the black walnut was introduced into Europe in 1629 and is also cultivated in Hawaii.[10]It is cultivated there and in North America as a forest tree for its high-quality wood. Black walnut plantings can be made to produce timber, nuts, or both timber and nuts. Patented timber-type trees were selected and released fromPurdue Universityin the early 1990s. These trees have been sporadically available fromnurseries.Varieties include Purdue #1, which can be used for both timber and nut production, though nut quality is poor compared to varieties selected specifically as nut producers.

Autumn foliage

Grafted,nut-producing trees are available from several nurseries operating in the U.S. Selections worth considering include Thomas, Neel #1, Thomas Myers, Pounds #2, Stoker, Surprise, Emma K, Sparrow, S127, and McGinnis. Several older varieties, such as Kwik Krop, are still in cultivation; while they make decent nuts, they would not be recommended for commercial planting.[13]

Pollination requirements should be considered when planting black walnuts. As is typical of many species in Juglandaceae,Juglans nigratrees tend to be monoecious, i.e.. producepollenfirst and thenpistillate flowersor else produce pistillate flowers and then pollen. An early pollen-producer should be grouped with other varieties that produce pistillate flowers so all varieties benefit from overlap. Cranz, Thomas, and Neel #1 make a good pollination trio. A similar group for more northern climates would be Sparrow, S127, and Mintle.

Sometimes black walnut is planted as part of reclaiming mines.[10]When growing young trees weed control is critical for healthy establishment of the trees, without weed control the young trees are harmed significantly in their growth rate.

Ornamental

[edit]

J. nigrais also grown as a specimen ornamental tree in parks and large gardens, growing to 30 m (100 ft) tall by 20 m (65 ft) broad.[14]It has gained theRoyal Horticultural Society'sAward of Garden Merit.[15][16]

Uses

[edit]
Walnut, black (J. nigra)
Black walnut
Nutritional value per 100 grams
Energy619 kcal (2,590 kJ)
9.6 g
Starch0.24 g
Sugars1.10 g
Dietary fiber6.8 g
59.3 g
Saturated3.5 g
Monounsaturated15.4 g
Polyunsaturated36.4 g
2.7 g
33.8 g
24.06 g
VitaminsQuantity
%DV†
Vitamin A40 IU
Thiamine (B1)
5%
0.057 mg
Riboflavin (B2)
10%
0.130 mg
Niacin (B3)
3%
0.470 mg
Pantothenic acid (B5)
33%
1.660 mg
Vitamin B6
34%
0.583 mg
Folate (B9)
8%
31 μg
Vitamin C
2%
1.7 mg
Vitamin E
14%
2.1 mg
Vitamin K
2%
2.7 μg
MineralsQuantity
%DV†
Calcium
5%
61 mg
Copper
156%
1.4 mg
Iron
17%
3.12 mg
Magnesium
48%
201 mg
Manganese
169%
3.896 mg
Phosphorus
41%
513 mg
Potassium
17%
523 mg
Selenium
31%
17 μg
Sodium
0%
2 mg
Zinc
31%
3.37 mg
Other constituentsQuantity
Water4.56 g
Link to USDA Database entry
†Percentages estimated usingUS recommendationsfor adults,[17]except for potassium, which is estimated based on expert recommendation fromthe National Academies.[18]

As food

[edit]
A bowl of black walnut kernels, shelled

Black walnut nuts are edible[19]and shelled commercially in the United States. About 65% of the annual wild harvest comes from the U.S. state ofMissouri,and the largest processing plant is operated by Hammons Products inStockton, Missouri.NPRaffiliateKCURstated in an article that "Ralph Hammons began the company in 1946 with a nut cracking machine acquired from Tennessee."[20]The StocktonBlack Walnut Festival,which has been held annually since 1961, "brings the community together for a 3-day event jam-packed with activities including a carnival, tractor pull, nut roll and 2-hour parade," stated Alexa Hodges in aVOXarticle.[21]The nutmeats provide a robust, distinctive, natural flavor and crunch as a food ingredient. Popular uses include ice cream, bakery goods and confections. Consumers include black walnuts in traditional treats, such ascakes,cookies,fudge,andpies,during the fall holiday season. The nuts' nutritional profile leads to uses in other foods, such assalads,fish,pork,chicken,vegetables and pasta dishes.

Tapped in spring, the tree yields a sweet sap that can be drunk or concentrated into syrup or sugar that is not unlike the sap ofsugar maple.[22]


Nut processing by hand

[edit]
Hand stains after removing the husks from black walnuts
The black walnut (on the left) is harder to process than the English walnut (on the right).

The extraction of the kernel from the fruit of the black walnut is difficult. The thick, hard shell is tightly bound by tall ridges to a thick husk. Rolling the nut underfoot on a hard surface such as a driveway is a common method; commercial huskers use a car tire rotating against a metal mesh. Some take a thick plywood board and drill a nut-sized hole in it (from one to two inches in diameter) and smash the nut through using a hammer. The nut goes through and the husk remains behind.[23]American pioneers let the nuts dry in the sun, then removed the husks and let the kernels dry—making them less bitter.[6]

The shell itself is thicker than that of the English walnut, and there are additional, thick internal walls tightly surrounding the nutmeat. Walnuts are too tough and too large to be opened with a standard nutcracker, but simply cracking the shell open with a rock results in smashed and shattered nutmeats mixed with shell, unless done with some care and skill—and it is still nearly impossible to extract an intact half this way. As a result, a number of home walnut-cracking devices have been produced, involving vices, cams, or levers.[24]

While the flavor of theJuglans nigrakernel is prized, the difficulty in preparing it may account for the wider popularity and availability of the English walnut.

Nutrition

[edit]

Black walnut kernels are 5% water, 59%fat,24%protein,and 10%carbohydrates.In a 100 gram reference amount providing 619calories,the kernels supply several nutrients in "rich" amounts (20% or more of theDaily Value,DV), including thedietary mineralsmanganese(186% DV) andphosphorus(73% DV), among others; andB vitaminsB6(45% DV) andpantothenic acid(33% DV). Black walnut kernels are a moderate source ofvitamin E(14% DV).[25]

Analysis of black walnut fat content showed the most prevalentfatty acidsarelinoleic acid(33.8%), followed byoleic acid(15.3%),alpha-linolenic acid(2.7%),palmitic acid(1.9%), andstearic acid(1.5%).[25]

Dye

[edit]

Black walnutdrupescontainjuglone(5-hydroxy-1,4-naphthoquinone),plumbagin(yellow quinone pigments), andtannin.These compounds cause walnuts to stain cars, sidewalks, porches, and patios, in addition to the hands of anyone attempting to shell them.[26] The brownish-black dye was used by early American settlers to dye hair.[27][better source needed]According to Eastern Trees in the Petersen Guide series, black walnuts make a yellowish-brown dye, not brownish-black. The apparent confusion is easily explained by the fact that the liquid (dye) obtained from the inner husk becomes increasingly darker over time, as the outer skin darkens from light green to black. Extracts of the outer, soft part of the drupe are still used as anatural dyefor handicrafts.[28] The tannins present in walnuts act as amordant,aiding in the dyeing process,[29][30]and are usable as a dark ink or wood stain.[31]

Industrial

[edit]

Walnut shells are often used as an abrasive in sand blasting or other circumstances where a medium hardness grit is required. The hard black walnut shell is also used commercially in abrasive cleaning, a filtering agent in scrubbers in smoke stacks, cleaning jet engines, cosmetics, and oil well drilling and water filtration.[10]

Wood

[edit]
Black walnut wood showing the color and grain
Juglans nigrawood in cross section

Black walnut is highly prized for its dark-colored, straight grained, true heartwood. It is heavy, strong, shock resistant and yet can be easily split and worked. Along with cedars (Thuja spp.), chestnut (Castanea spp.), and black locust (Robinia pseudoacacia) black walnut is one of the most durable hardwoods in the US.[10]The wood can be kiln dried and holds its shape well after seasoning, which makes this wood even more attractive for wood working.[10]

Walnut wood has historically been used forgun stocks,furniture, flooring, paddles, coffins, and a variety of other wood products.[10]Black walnut has a density of 660 kg per cubic meter (41.2 lb/cubic foot),[32]which makes it less dense than oak.

Pests

[edit]

Maggots(larvae ofRhagoletis completaandRhagoletis suavis) in the husk are common, though more a nuisance than a serious problem for amateurs, who may simply remove the affected husk as soon as infestation is noticed. The maggots develop entirely within the husk, thus the quality of the nutmeat is not affected.[33]However, infestations of maggots are undesirable because they make the husk difficult to remove and are unsightly. Maggots can be serious for commercial walnut growers, who tend to use chemical treatments to prevent damage to the crop.[34]Some non-chemical controls also exist, such as removing and disposing of infested nuts.[35]

The walnutweevil(Conotrachelus retentus) grows to5 millimetres (3⁄16in) long as an adult. The adult sucks plant juices through a snout. The eggs are laid in fruits in the spring and summer. Many nuts are lost due to damage from the larvae, which burrow through the nut shell.[36]

Black walnut is affected by European canker (Neonectria galligena). The infection spreads slowly but infected trees eventually die.[10]

Walnut caterpillars

The walnut caterpillar (Datana integerrima) and fall webworm (Hyphantria cunea) are two of the most serious pests, they commonly eat the foliage in midsummer and continue into autumn.

Codling moth (Cydia pomonella) larvae eat walnut kernels, as well as apple and pear seeds.[37]

Important leaf sucking insects include species ofaphidsand plant lice including (Monelliaspp. andMonelliopsisspp.), which suck the juices from leaves and often deposit a sticky substance called "honey-dew" on the leaf surface that may turn black and prevent photosynthesis; and the walnut lace bug (Corythucha juglandis), which causes damage when the adults and nymphs suck the sap from the lower surfaces of walnut leaflets.[7]

A disease complex known asthousand cankers diseasehas been threatening black walnut in several western states.[38]This disease has recently been discovered in Tennessee, and could potentially have devastating effects on the species in the eastern United States.[39]Vectored by the walnut twig beetle (Pityophthorus juglandis), a fungus,Geosmithia morbida,spreads into the wood around the galleries carved by the small beetles. The fungus causes cankers that inhibit the movement of nutrients in black walnut, leading to crown and branch dieback, and ultimately death.[40]

Allelopathy

[edit]

While black walnut is consideredallelopathic,meaning it excretes chemicals into its environment that harm competition, research from 2019 has questioned whether this long-held belief holds up to scientifically rigorous examination. Many publications that have repeated claims of black walnut allelopathy cite a very limited set of dated research literature, which has not held up to scientific scrutiny.[2]Anecdotally, records of walnut toxicity to other plants have been observed as far back as the first century whenPliny the Elderwrote: "The shadow of walnut trees is poison to all plants within its compass."[41]

Like otherwalnuts,the roots, inner bark, nut husks, and leaves contain a nontoxic chemical called hydrojuglone;[41]when exposed to air or soil compounds it is oxidized intojuglonethat is biologically active and acts as a respiratory inhibitor to some plants. Juglone is poorly soluble in water and does not move far in the soil and will stay most concentrated in the soil directly beneath the tree.[42]Even after a tree is removed the soil where the roots once were will still contain juglone for several years after the tree is removed as more juglone will be released as the roots decay.[42]Well drained and aerated soils will host a healthy community of soil microbes and these microbes will help to break down the juglone.

Symptoms of juglone poisoning include foliar yellowing and wilting.[42]A number of plants are particularly sensitive. Apples, tomatoes, pines, and birch are poisoned by juglone, and as a precaution, should not be planted in proximity to a black walnut.[7][43]

Interaction with horses

[edit]

Horses are susceptible tolaminitisfrom exposure to black walnut wood in bedding.[44]

Largest trees

[edit]

TheUS national championblack walnut is on a residential property onSauvie Island,Oregon.It is 8 ft 7 in (2.62 m)diameter at breast heightand 112 ft (34 m) tall, with a crown spread of 144 feet (44 m).[45]

The largest known living black walnut tree is on Sauvie Island, Oregon.

The tallest black walnut in Europe is located in the Woluwe Park in the city of Sint-Pieters-Woluwe, Brussels, Belgium. It has a circumference of 3.50 m (11 ft 6 in), height of exactly 33.60 m (110.2 ft) (measured by laser), and was planted around 1850 (± 10 years).[46]

The largest black walnut in Europe is located in the Castle Park in the city ofSereď,Slovakia. It has a circumference of 6.30 m (20 ft 8 in), height of 25 m (82 ft) and estimated age of 300 years.[47]

See also

[edit]

References

[edit]
  1. ^Stritch, L. (2018)."Juglans nigra".IUCN Red List of Threatened Species.2018:e.T62019712A62019714.doi:10.2305/IUCN.UK.2018-1.RLTS.T62019712A62019714.en.Retrieved19 November2021.
  2. ^abChalker-Scott, Linda.Do black walnut trees have allelopathic effects on other plants?.rex.libraries.wsu.edu(Report). Home Garden Series.hdl:2376/14212.Archivedfrom the original on 19 September 2022.Retrieved2022-09-18.
  3. ^abPeterson, George A. Petrides; illustrations by George A. Petrides, Roger Tory (1986).A field guide to trees and shrubs: northeastern and north-central United States and southeastern and south-central Canada(2nd ed.). Boston: Houghton Mifflin.ISBN0-395-13651-2.{{cite book}}:CS1 maint: multiple names: authors list (link)
  4. ^abcdefDirr, Michael A (1990).Manual of woody landscape plants(4. ed., rev. ed.). Champaign, Illinois: Stipes Publishing Company.ISBN0-87563-344-7.
  5. ^Rhoads, Ann; Block, Timothy (5 September 2007).The Plants of Pennsylvania(2 ed.). Philadelphia Pa: University of Pennsylvania press.ISBN978-0-8122-4003-0.
  6. ^abcAngier, Bradford(1974).Field Guide to Edible Wild Plants.Harrisburg, PA: Stackpole Books. p. 38.ISBN0-8117-0616-8.OCLC799792.
  7. ^abcdefghijklWilliams, Robert D. (1990)."Juglans nigra".In Burns, Russell M.; Honkala, Barbara H. (eds.).Hardwoods.Silvics of North America.Vol. 2.Washington, D.C.:United States Forest Service(USFS),United States Department of Agriculture(USDA).Retrieved2016-06-29– via Southern Research Station.
  8. ^http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/juglans/nigra.htm
  9. ^Whittemore, Alan T.; Stone, Donald E. (1997)."Juglans".In Flora of North America Editorial Committee (ed.).Flora of North America North of Mexico (FNA).Vol. 3. New York and Oxford: Oxford University Press – via eFloras.org,Missouri Botanical Garden,St. Louis, MO &Harvard University Herbaria,Cambridge, MA.
  10. ^abcdefghijColadonato, Milo (1991)."Juglans nigra".Fire Effects Information System (FEIS).US Department of Agriculture (USDA), Forest Service (USFS), Rocky Mountain Research Station, Fire Sciences Laboratory.Retrieved2016-06-29.
  11. ^Tirmenstein, D. A. (1990)."Juglans microcarpa".Fire Effects Information System (FEIS).US Department of Agriculture (USDA), Forest Service (USFS), Rocky Mountain Research Station, Fire Sciences Laboratory.Retrieved2016-06-29.
  12. ^"How can I germinate walnuts?".Iowa State University.Retrieved3 December2022.
  13. ^"Flowering and Fruit Characteristics of Black Walnuts: A Tool for Identifying and Selecting Cultivars".University of Missouri Extension.Retrieved2021-10-29.
  14. ^RHS A-Z encyclopedia of garden plants.United Kingdom: Dorling Kindersley. 2008. p. 1136.ISBN978-1-4053-3296-5.
  15. ^"Juglans nigra".Royal Horticultural Society.Retrieved25 September2020.
  16. ^"AGM Plants - Ornamental"(PDF).Royal Horticultural Society. July 2017. p. 56.Retrieved14 March2018.
  17. ^United States Food and Drug Administration(2024)."Daily Value on the Nutrition and Supplement Facts Labels".FDA.Archivedfrom the original on 2024-03-27.Retrieved2024-03-28.
  18. ^National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.).Dietary Reference Intakes for Sodium and Potassium.The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US).ISBN978-0-309-48834-1.PMID30844154.Archivedfrom the original on 2024-05-09.Retrieved2024-06-21.
  19. ^Lyle, Katie Letcher (2010) [2004].The Complete Guide to Edible Wild Plants, Mushrooms, Fruits, and Nuts: How to Find, Identify, and Cook Them(2nd ed.). Guilford, CN:FalconGuides.p. 134.ISBN978-1-59921-887-8.OCLC560560606.
  20. ^Bailey, Hogan, Natasha, Suzanne (December 7, 2022)."Black walnuts don't get as much love as non-native nuts. These Missourians want to change that".NPR.KCUR.Retrieved8 December2022.{{cite news}}:CS1 maint: multiple names: authors list (link)
  21. ^Hodges, Alexa (September 28, 2018)."What you should know before you go to the Black Walnut Festival".VOX.Retrieved8 December2022.
  22. ^"Tapping Walnut Trees for a Novel and Delicious Syrup".Cornell Small Farms Program.2016-01-11.Retrieved2019-02-01.
  23. ^Mason, Sandra."Preparing Black Walnuts for Eating".University of Illinois Extension.Retrieved2014-07-26.
  24. ^John Sankey."Black Walnut Crackers".Retrieved2020-11-24.
  25. ^abU.S. Department of Agriculture(2019-04-01)."FoodData Central: Nuts, walnuts, black, dried".fdc.nal.usda.gov.Retrieved2023-06-27.
  26. ^"Black Walnut Uses, Benefits & Dosage – Drugs.com Herbal Database".
  27. ^"Legumes, Nuts, Seeds & discussion".www.faculty.ucr.edu.
  28. ^Black Walnut Basket DyeArchived2008-10-10 at theWayback Machine
  29. ^"Fixing natural dyes from walnuts, goldenrod, sassafras and poke weed in cotton – do I use urea or soda ash?".www.pburch.net.
  30. ^"Dyeing with Tannic Acid and Iron: Walnut Husks (2005)"(PDF).
  31. ^Making Walnut Ink.Madame Elizabeth de Nevell.
  32. ^Niche Timbers Black WalnutArchived2008-08-11 at theWayback Machine
  33. ^Walnut Husk Maggot,Rhagoletis suavis(Loew) and Walnut Husk Fly,Rhagoletis completaCresson
  34. ^Walnut Husk MaggotArchived2008-10-11 at theWayback Machine.Ontario Ministry of Agriculture, Food and Rural Affairs.
  35. ^"Walnut Husk Fly Management Guidelines – UC IPM".www.ipm.ucdavis.edu.
  36. ^"Northeastern Area State and Private Forestry".na.fs.fed.us.
  37. ^"Codling Moth Management Guidelines – UC IPM".www.ipm.ucdavis.edu.
  38. ^"Pest Alert: Walnut Twig Beetle and Thousand Cankers Disease of Black Walnut"(PDF).Purdue University: Purdue Pest & Plant Diagnostic Laboratory. Archived fromthe original(PDF)on 2010-06-28.Retrieved2010-08-06.
  39. ^"Bill Poovey. Black walnut tree thousand canker first in East US.Times Union.Posted July 30, 2010 ".
  40. ^"Page Not Found – Clemson University, South Carolina".www.clemson.edu.{{cite web}}:Cite uses generic title (help)
  41. ^abRietvelt, W. J (1983)."Allelopathic effects of juglone on germination and growth of several herbaceous and woody species"(PDF).Journal of Chemical Ecology.9(2): 295–308.Bibcode:1983JCEco...9..295R.CiteSeerX10.1.1.550.5739.doi:10.1007/BF00988047.PMID24407348.S2CID23491349.Retrieved2 July2016.
  42. ^abc"Black walnut toxicity"(PDF).Purdue University.Retrieved30 June2016.
  43. ^"Black Walnut Toxicity".West Virginia University. Archived fromthe originalon 12 February 2015.Retrieved3 July2014.
  44. ^"Laminitis Caused by Black Walnut Wood Residues"(PDF).Purdue University. January 2005. Archived fromthe original(PDF)on 14 June 2010.Retrieved9 March2009.
  45. ^"Oregon Champion Tree Registry".ascendingthegiants.com.2013. Archived fromthe originalon 2016-03-08.
  46. ^"Zwarte walnoot in het park van Woluwe, Sint-Pieters-Woluwe, Brussel, België".
  47. ^Majko, Majko Design Studio - Miloš."Mesto Sereď má unikátny strom Juglans nigra nominovaný v súťaži Strom roka 2012 - SereďOnLine".

Further reading

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