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Juglans nigra – Wikipedia

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**Botanical Description**:
– Odor: Pungent or spicy odor in leaves, stems, and fruit husks.
– Trunk Height: 30–40m (100–130ft).
– Bark: Grey-black, deeply furrowed.
– Pith: Chambered, light brown.
– Leaves: Pinnately compound, dark green, hairy underside, with serrated edges.
– Flowers: Monoecious, wind-pollinated catkins, dichogamy.
Fruit: Spherical with brownish-green husk, small hard seed, irregular fruiting.
– Ecology: Pioneer species, native range across eastern US, absent from coastal plain south of North Carolina.

**Cultivation and Uses**:
– Native to the Midwest and east-central United States.
– Introduced to Europe in 1629, also cultivated in Hawaii.
– Cultivated for high-quality wood, grafted nut-producing trees available.
– Used as specimen ornamental tree, reaching 30m tall and 20m broad.
– Edible nuts commercially harvested in the US, used in various food items.
Sap used to make syrup or sugar, rich in nutrients like manganese and B vitamins.

**Wood and Dye**:
– Prized for dark-colored, straight-grained, true heartwood.
– Heavy, strong, shock-resistant, and easily worked.
– Kiln dried, historically used for gun stocks, furniture, and more.
– Black walnut drupes contain compounds used for dyeing.
– Dye extracted from walnuts used to stain surfaces, make yellowish-brown dye.
– Tannins in walnuts used as mordant for dyeing or as wood stain.

**Pests and Allelopathy**:
– Common pests include walnut weevil, European canker, and codling moth.
– Thousand cankers disease poses a threat to black walnut trees.
– Allelopathic effects of juglone inhibit growth of sensitive plants.
– Symptoms of juglone poisoning include foliar yellowing and wilting.
– Interaction with horses: Exposure to black walnut wood can cause laminitis.

**Resources and Further Reading**:
– Various sources cited for information on black walnut.
Nutrition information: Rich in nutrients, FDA sets daily values.
– Pest management guidelines provided by UC IPM and Ontario Ministry of Agriculture.
– Toxicity risks highlighted by Purdue University and West Virginia University.
– Additional resources: Books, field guides, and growing guides available for further reading.

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