Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Juglans nigra L.
- Family: Walnut (Juglandaceae)
- Flowering: April-June
- Field Marks: This species is recognized by its soft-hairy buds, its tan-colored chambered
pith, its distinct aroma, and its fruits.
- Habitat: Rich woods.
- Habit: Large tree up to 150 feet tall, with a trunk diameter up to 5 feet; crown broadly rounded; bark black, thick, deeply furrowed.
- Twigs: Stout, greenish or orange-brown, hairy or smooth; pith tan to light brown, divided by partitions; leaf scars alternate, shield-shaped, with 3 bundle traces; buds soft-hairy, up to 1/2 inch long.
- Leaves: Alternate on the stem, pinnately compound, with 15-23 leaflets; leaflets opposite or subopposite on the rachis, up to 3 1/2 inches long and 1 1/2 inches wide, broadly lanceolate, pointed at the tip, rounded at the asymmetrical base, toothed, yellow-green and smooth above, paler and hairy below.
- Flowers: Borne separately but on the same tree, appearing when the leaves are partly grown, the male several in thick, yellow-green, hairy spikes, the female much fewer in small spikes.
- Sepals: 0.
- Petals: 0.
- Stamens: 1.
- Pistils: Ovary inferior.
- Fruits: In groups of 1 or 2, spherical, up to 2 inches in diameter, green or yellow-green, slightly roughened, the husk thick, the nut very hard, oval, dark brown, deeply ridged, the seed sweet.
- Notes: The nut is edible and used for flavoring, including ice cream. The wood is extremely valuable for making furniture, interior finishing, gun stocks, and cabinets. The fruit husks were used by Indians and colonists as a dye. The plant contains allelopathic chemical compounds which restrict the growth of many plants.
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