Juglans nigra, the eastern American black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central Texas. Wild trees in the upper Ottawa Valley may 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. Walnut seeds (nuts) are cultivated for their distinctive and desirable taste. Walnut trees are grown both for lumber and food, and many cultivars have been developed for improved quality wood or nuts. Black walnut is susceptible to thousand cankers disease that provoked a decline of walnut trees in some regions.

Black walnut is known for being allelopathic, which means that it releases chemicals from its roots and other tissues that harm other organisms and give the tree a competitive advantage.

Black Walnuts scientifically known as Juglans nigra is a species of deciduous tree in the walnut family, Juglandaceae, native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida, and southwest to central Texas. Wild trees in the upper Ottawa Valley may be an isolated native population or may have derived from planted trees. Apart from Black walnut, it is also known as American walnut and eastern black walnut. Most parts of the tree including leaves, stems, and fruit husks have a very characteristic pungent or spicy odor. Black walnuts are popular food sources in both America and Europe and can be found in everything from candy, ice cream, fudge, and salads, as well as chicken, pork, and pasta dishes.

Black Walnuts Scientific Classification

Scientific Name: Juglans nigra

Plant

Black walnut is actually a large deciduous hardwood tree growing up to 70 feet tall and 70 feet wide. It is found growing 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 needs full sun for optimal growth and nut production. It prefers deep, fertile soil with a near-neutral or slightly acidic ph. It also tolerates relatively dry, poor soils, but with a considerably reduced growth rate. The black walnut tree has a deep & strong taproot as long as 10 feet with typically grey-black bark and is deeply furrowed into thin ridges which gives the bark a diamond-shaped pattern. It has a huge trunk. Under forest competition, it develops a tall and straight trunk and when grown in an open area it has a short trunk and broad crown. Leaves are alternate, compound, 1–2 feet long, with 11–23 leaflets. Leaflets are 3–5 inches long, 1–2 inches wide, broadest below the middle, the end leaflet is smaller than side ones or absent; margin toothed. The leaves are overall dark green in color and are typically paler, hairy on the underside. Flowers are monoecious. The male (staminate) flowers are in drooping catkins 8–10 cm (3 1⁄4–4 in) long. These are borne from axillary buds on the previous year’s growth. The female flowers are terminal, in clusters of two to five on the current year’s growth. Flowering normally takes place from April to May.

• Odor Most parts of the tree including leaves, stems, and fruit husks have a very characteristic pungent or spicy odor. This odor is lacking in the nut itself.^[rx][rx]
• Trunk Height 30–40 m (100–130 ft). Under forest competition, it develops a tall and straight trunk. When grown in an open area it has a short trunk and broad crown.^[rx]
• Bark The bark is typically grey-black and deeply furrowed into thin ridges that give the bark a diamond-shaped pattern.^[rx]
• Pith The pith of the twigs is chambered and light brown.^[rx]
• Buds The buds are pale silky and covered in downy hairs. The terminal buds are ovate, and 8 mm (5⁄16 in) long, and slightly longer than broad, the lateral buds are smaller and superposed.^[rx]
• Leaves The leaves are pinnately compound and alternately arranged on the stem. They are 30–60 cm (1–2 ft) long, typically even-pinnate but there is heavy variation among leaves. The stems have 15–23 leaflets, when the terminal leaf is included, with the largest leaflets located in the center, 7–10 cm (2+3⁄4–4 in) long and 2–3 cm (3⁄4–1+1⁄4 in) broad.^[rx] The leaflets have a rounded base and a long pointed (acuminate) tip as well as having a serrated edge.^[rx] The leaves are overall dark green in color and are typically hairy on the underside.
• Leaf scar The leaf scar has 3 prominent bundle scars^[rx] and has a notch on the side that points toward the tip of the branch (distal side)
• Flowers Black walnut is monoecious. The male (staminate) flowers are in drooping catkins 8–10 cm (3+1⁄4–4 in) long. These are borne from axillary buds on the previous year’s growth. The female (pistillate) flowers are terminal, in clusters of two to five on the current year’s growth.^[rx]
• Fruit Ripens during the summer/

Fruit

The fruit of Black Walnut is made of an inner kernel, enclosed by a hard corrugated round shell composed of two fused halves. This in turn is surrounded by a thick outer husk that is green when immature, and yellow-black when ripe. If ripe fruits are picked up, a brown-black dye will easily seep from the moist husk into the skin of your hand, rendering them stained for a couple of days. The kernel is oily, sweet, and edible. It has a robust, distinctive, natural flavor and the peak season of the black walnut is from September to October. Fruiting may begin when the tree is 4–6 years old; however large crops take 20 years. Since black walnuts are popular food sources in both America and Europe, it can be found in everything from candy, ice cream, fudge, and salads, as well as chicken, pork, and pasta dishes.

History

Black walnut is native to eastern North America, where it grows, mostly alongside river banks, from southern Ontario, South Dakota, Northern Florida, Central Texas and even in Canada Black walnut trees are found in forests and are now also cultivated even in Europe for its high-quality wood and nuts. Black walnut has a long history of use even from ancient times as a wood source and for its delicious nuts. Currently, it is grown throughout the world because of its wonderful nutritional value.

Minerals	Amount	% DV
Calcium, Ca	76 mg	7.60%
Iron, Fe	3.9 mg	48.75%
Magnesium, Mg	251 mg	59.76%
Phosphorus, P	641 mg	91.57%
Potassium, K	654 mg	13.91%
Sodium, Na	2 mg	0.13%
Zinc, Zn	4.21 mg	38.27%
Copper, Cu	1.7 mg	188.89%
Manganese, Mn	4.87 mg	211.74%
Selenium, Se	21.2 µg	38.55%

Vitamins	Amount	% DV
Water-soluble Vitamins
Vitamin B1 (Thiamin)	0.071 mg	5.92%
Vitamin B2 (Riboflavin)	0.162 mg	12.46%
Vitamin B3 (Niacin)	0.588 mg	3.68%
Vitamin B5 (Pantothenic acid)	2.075 mg	41.50%
Vitamin B6 (Pyridoxine)	0.729 mg	56.08%
Vitamin B9 (Folate)	39 µg	9.75%
Folate, food	39 µg	N/D
Folate, DEF	39 µg	N/D
Choline	40.1 mg	7.29%
Vitamin C (Ascorbic acid)	2.1 mg	2.33%
Fat-soluble Vitamins
Vitamin A, RAE	2 µg	0.29%
Vitamin A, IU	50 IU	N/D
Beta Carotene	30 µg	N/D
Betaine	0.6 mg	N/D
Lutein + zeaxanthin	11 µg	N/D
Vitamin E (alpha-tocopherol)	2.6 mg	17.33%
Tocopherol, beta	0.01 mg	N/D
Tocopherol, gamma	35.98 mg	N/D
Tocopherol, delta	1.89 mg	N/D
Vitamin K (phylloquinone)	3.4 µg	2.83%

Lipids	Amount	% DV
Fatty acids, total saturated	4.354 g	N/D
Palmitic acid 16:00 (Hexadecanoic acid)	2.418 g	N/D
Stearic acid 18:00 (Octadecanoic acid)	1.936 g	N/D
Fatty acids, total monounsaturated	19.302 g	N/D
Palmitoleic acid 16:1 (hexadecenoic acid)	0.052 g	N/D
Oleic acid 18:1 (octadecenoic acid)	18.91 g	N/D
Gadoleic acid 20:1 (eicosenoic acid)	0.34 g	N/D
Fatty acids, total polyunsaturated	45.546 g	N/D
Linoleic acid 18:2 (octadecadienoic acid)	42.2 g	N/D
18:2 n-6 c,c	42.2 g	N/D
Linolenic acid 18:3 (Octadecatrienoic acid)	3.346 g	N/D
18:3 n-3 c,c,c (ALA)	3.346 g	N/D
Beta-sitosterol	144 mg	N/D

Amino acids	Amount	% DV
Tryptophan	0.398 g	90.45%
Threonine	0.901 g	51.19%
Isoleucine	1.208 g	72.25%
Leucine	2.105 g	56.95%
Lysine	0.891 g	26.64%
Methionine	0.584 g	N/D
Cystine	0.578 g	N/D
Phenylalanine	1.368 g	N/D
Tyrosine	0.925 g	N/D
Valine	1.589 g	75.24%
Arginine	4.522 g	N/D
Histidine	0.84 g	68.18%
Alanine	1.31 g	N/D
Aspartic acid	3.041 g	N/D
Glutamic acid	6.44 g	N/D
Glycine	1.486 g	N/D
Proline	1.158 g	N/D
Serine	1.531 g	N/D

*Above mentioned Percent Daily Values (%DVs) are based on 2,000 calorie diet intake. Daily values (DVs) may be different depending upon your daily calorie needs. Mentioned values are recommended by the U.S. Department of Agriculture. They are not healthbenefitstimes.com recommendations. Calculations are based on average age of 19 to 50 years and weigh 194 lbs. Source: https://ndb.nal.usda.gov/ 

Health Benefits of Black Walnut

Also known as Juglans nigra, this dark-colored nut originated from North America. Dating back to thousands of years ago, Native Americans, as well as Romans, considered it extremely prized for its ability to treat intestinal problems as well as skin disorders. Here’s a close look at the health benefits of black walnut

1. Cancer

Several direct types of research have been done on the anti-cancer effects of black walnuts, and the results have been very promising so far. The organic compound juglone found in black walnut, along with many other polyphenolic compounds and fatty acids, contributes to anti-tumor and anti-carcinogenic activity within the body, slowing the growth or preventing the development of numerous types of cancer.(1)

2. Antifungal Action

Candida albicans is a very common agent in the body that causes yeast infections. Candida fungus can easily get into the body and is exacerbated by poor dietary habits. Black walnut, however, consists of juglone and tannins that can make the environment of the gut very unfriendly to the candida fungus, thus protecting the body from this fungus, which can weaken blood vessel walls and increase toxicity in your bloodstream. This same antifungal action makes black walnut effective against Athlete’s foot, ringworm, jock itch, and other more common fungal infections.(2)

3. Beneficial for Hair

Black walnut holds strong contents of omega fatty acids which help hair follicles to stay strong, smooth, and lustrous. Baldness, hair loss, dry hair, and dandruff are some of the issues that can be met by the proper intake of black walnuts. You can also maintain the healthy color of your hair due to the coloring agents present in it.

4. Expels Parasites

One of the key active components of the black walnut hull is the juglone. Juglone exerts its effect by inhibiting certain enzymes required for metabolic function. It’s extremely toxic to many insect herbivores — it’s often used by organic gardeners as a natural pesticide — and researchers have observed that black walnut can expel parasitic worms from the body.

According to the Pharmaceutical Society of Australia, black walnut is quite effective against ringworm, tapeworm, pin or threadworm, as well as other parasites of the intestine. This is why black walnut makes a great addition to any parasite cleanse.(3)

5. Helps with weight loss

Regular consumption of a few black walnuts in your diet will help in enhancing your metabolism. These nuts also help in reducing the total fat content. Plus, it also prevents sugar level variations that could prevent you from overeating. To be precise, black walnuts help you shed the excess fat and tone yourself.

6. Immune System Health

Along with its antifungal activity to boost the health of the immune system, black walnut is also rich in antioxidants, meaning that it can considerably contribute to the protection of the body by neutralizing free radicals that can cause particular types of cancer and chronic disease. Black walnut is also antiviral and anti-parasitic in nature, providing a comprehensive defensive line for your body.(4)

7. Improved Reproduction in Men

It is one of the remarkably lesser-known benefits of black walnuts. Black walnuts play an important role in the male reproductive system by increasing male fertility. The sperm quality is improved as it controls the vitality, motility, and morphology of the cells.

8. Digestive Health

The natural anti-inflammatory activity of black walnut makes it ideal for calming upset stomachs, mainly inflamed walls of the colon or gut, which help to normalize the digestive process and regulate excretion. Black walnut is supposed to help relieve both constipation as well as diarrhea, efficiently balancing the body’s entire gastrointestinal system. Some people use black walnuts as a laxative substance in concentrated doses, but this isn’t suggested for extended periods of time.(5)

9. Respiratory Conditions

Gargling with black walnut extract can be effective for soothing sore throats, as the anti-inflammatory nature can relieve irritation and inflammation.(6)

10. Heart Health

A high level of omega-3 fatty acids and beneficial compounds contained in black walnuts is vital for heart health. Eating a few extra walnuts each day can help to normalize the cholesterol levels in your body, as omega-3 fatty acids can help to eradicate dangerous LDL cholesterol from the body. This can help to lower your blood pressure, ease tension on your cardiovascular system, decrease the chance of developing atherosclerosis, and thus lower your risk of heart attack, stroke, and coronary heart disease.(7)

11. Skin Health

By crushing up black walnut husks, a fine powder can be created and made into a paste for the skin. The rich levels of antioxidants and beneficial fatty acids can actually impact the health and appearance of the skin, preventing blemishes and pimples, preventing acne, and clearing up skin conditions like psoriasis and eczema. Direct use of the powder tincture may be too strong for the skin, thus it can be mixed in with other carrier creams and natural salves.

12. For Blood Sugar or Diabetes

Dietary fats present in black walnuts are seen to improve your metabolic parameters if you have type-2 diabetes. Commonly, it is seen that if you have obesity, you are likely to have type-2 diabetes.

If regular consumption of black walnuts is done in sufficient quantity, then you can deal with this problem, and it will help you maintain blood sugar levels. This is seen to happen by a reduction in fasting insulin levels.

13. Improves sleep

Black walnuts are a rich source of melatonin, a hormone and antioxidant known to regulate day-night cycles, guard cells, and DNA and reduce inflammation levels. Having sufficient melatonin in your system is the key to sleeping better. But because the body decreases production as we age, including either plant sources such as black walnuts or (melatonin) food supplements in your diet might help improve your sleep significantly.

https://www.youtube.com/watch?v=1ot-cJNY-s8

How to Eat

• Consumers include black walnuts in traditional treats, such as cakes, cookies, fudge, and pies, during the fall holiday season.
• It is also used in other foods, such as salads, fish, pork, chicken, vegetables, and pasta dishes.

Other Traditional uses and benefits of Black Walnuts

• Black Walnut has been historically used to get rid of a fever and treat kidney ailments, gastrointestinal concerns, ulcers, toothache, snake bites, and syphilis.
• Husks of the black walnut contain chemicals that prevent bacterial and fungal growth and may be valuable in controlling dermal, mucosal, and oral infections in humans.
• Black walnut is useful in the treatment of skin diseases such as herpes and eczema.
• Traditionally it is used as a natural remedy for acne, canker sores, psoriasis, and other fungal infections.
• Juice of the fruit husk may be applied externally as a treatment for ringworm or applied as a poultice for inflammations.
• Oil from the ripe nuts is a traditional remedy for gangrene, leprosy, and wounds.
• Nuts of the black walnut are supposed to aid in decreasing cholesterol levels and improve overall heart health and function.
• The presence of Omega-3 fatty acids in the fruit of the black walnut helps reduce inflammation and promote the function of the lungs; this may give relief from asthma.
• An infusion of the bark is used to treat diarrhea and also to stop the production of milk, though a strong infusion can be emetic.
• The bark is chewed to calm the pain of toothache and it is also used as a poultice to reduce the pain of headaches.
• The husk is chewed in the treatment of colic and applied as a poultice to inflammations.
• Burnt kernels, taken in red wine, are said to prevent falling hair, making it fair.
• Green husks are supposed to ease the pain of toothache.
• Tea made from the leaves is astringent.
• An infusion has been used to lower high blood pressure.
• Oil from the ripe seeds has been used externally in the treatment of gangrene, leprosy, and wounds.
• Sap has been used to treat inflammations.

Other Facts

• Black walnut plantings can be made to produce timber, nuts, or both timber and nuts.
• Walnut shells are frequently used as an abrasive in sandblasting or other circumstances where medium hardness grit is required.
• Hard black walnut shell is also used commercially in abrasive cleaning, a filtering agent in scrubbers in smokestacks, cleaning jet engines, cosmetics, and oil well drilling and water filtration.
• A brown dye is obtained from the nuts, husks, and bark.
• Green fruit husks can be boiled to provide a yellow dye.
• Woody shells on the fruits have been used to make jewelry.
• Insects are said to avoid the walnut tree, hence it is often used as a poor man’s insect repellent.
• They are also used as an insecticide against bed bugs.

Precautions

• For patients with nut allergies, an allergic reaction to black walnut may result in rashes, itchy and swollen skin, hives, chest pain, or problems with breathing.
• Black walnut is not recommended for pregnant or breastfeeding women or for extended periods of time.
• Caution is advised in patients who take blood pressure measure medication because black walnut may alter the drug.
• Fresh green husk can cause irritation and blistering when applied to the skin in excessive quantities.
• Taken internally in huge doses, it’s a sedative to the circulation system and heart.
• Copious intake of black walnuts can lead to liver and kidney abnormalities and can even lead to their damage.
• Uncontrolled consumption of walnuts can lead to weight gain due to their high percentage of energy content.

References

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