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Native Species
Juglans nigra (Black Walnut)
Breadcrumb
Common Name
It is commonly referred to as Black Walnut
Scientific Name
Scientific name:
Species: Juglans nigra
Plant Context
This species has no specified origin
Overview
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<p>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.</p> <p>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, which provoked a decline of walnut trees in some regions.</p> <p>Black walnut is anecdotally known for being allelopathic, 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.</p>
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How to Identify
How To Identify
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. It can grow up to 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. The bark is typically grey-black and deeply furrowed into thin ridges that gives the bark a diamond shaped pattern. 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 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. The leaflets have a rounded base and a long pointed (acuminate) tip as well as having a serrated edge. The leaves are overall dark green in color and are typically hairy on the underside. Fruit Ripens 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.
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