Black Walnut

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Black Walnut

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Black Walnut Tree

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Black Walnut Leaves

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Black Walnut Catkins

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Black Walnut Bark

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Black Walnut Twig Cross Section

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Juglans nigra
Juglandaceae (walnuts)

A large tree with a straight trunk and rounded, open crown. The nuts, spicy odor, large feather-compound leaves, and chambered pith in the twigs help identify it.

Leaves alternate, compound, 1–2 feet long, with 11–23 leaflets. Leaflets 3–5 inches long, 1–2 inches wide, broadest below the middle, the end leaflet smaller than side ones or absent; margin toothed; upper surface yellow-green; lower surface paler, hairy.

Bark grayish-brown or black, grooves deep, ridges broad with sharp or rounded edges, roughly forming diamond-shaped patterns, chocolate-colored when cut.

Twigs stout, rigid, brown to gray-brown, hairy; end bud about ½ inch long; pith light brown, chambered when cut lengthwise.

Flowers April–May. Male flowers in catkins, female flowers in a short spike on the same tree.

Fruits September–October, usually single or in pairs. A green rounded husk, 1½-2½ inches across, covers the round, hard, bony, dark brown or black nut. The kernel is oily, sweet, and edible.

Height: to 90 feet.
Habitat and conservation: 
Walnut grows throughout Missouri in a variety of soils. It grows best on the deep, well-drained soils of north Missouri and on alluvial soils in the south. Every farm in the state should grow some walnut trees. In addition to providing valuable wood, the walnut’s nutmeats are a major industry in the state. Even the hard shells can be used as an abrasive and to make activated carbon. It is Missouri’s most valuable tree.
Distribution in Missouri: 
Black walnut has been designated as Missouri's official state tree nut. Most of the state’s large, old walnut trees were felled in previous decades for lumber and other uses, yet the superb wood from this species remains in high demand. Young landowners have been planting walnuts in hopes of harvesting them in future decades.
Human connections: 
Missouri’s the world’s top producer of black walnuts, which are used in baking and confections and even pickled whole. Walnut is the finest wood in the world. In the past, the warm brown hardwood was used lavishly in homes, barns, and fences. Today it’s used for furniture, veneer, and gunstocks.
Ecosystem connections: 
The nuts are eaten by mice and squirrels. The leaves are eaten by larvae of luna moths, regal moths, and others. The presence of such caterpillars naturally attracts warblers and other insectivorous birds. Walnut trees produce a chemical, juglone, that stunts or kills other plants growing nearby.
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