Black Walnut
Black
Walnut (Juglans nigra /Juglandaceae). Black
walnut is native to the eastern United States, from southern Minnesota
east to Pennsylvania, New Jersey, New York; south to South Carolina,
Georgia, Florida, Alabama; west to Texas; and north
through Oklahoma, Kansas, Nebraska, and South Dakota. Black walnut
trees reach heights of 120 ft (37 m), with a diameter of over
3 ft (1 m). Juglans nigra sapwood is light tan, with the heartwood
being a dark, chocolate brown, sometimes having a purplish cast.
Juglans nigra is hard, heavy, hard and stiff (high shock resistance).
The wood has a straight grain, is easily worked, finishes well
and holds paint and stain. It is a most durable wood, even under
conditions favorable to decay (moist conditions). It is used for
cabinets, fixtures, furniture, gunstocks, interior paneling, novelties
and veneer.
http://ufei.calpoly.edu/urbanwood/woodproperties.lasso#content.
Characteristics found in the American
Black Walnut (Juglans nigra):
- Semi-Ring Porous
- Reticulate parenchyma
- Tyloses & deposits
- Simple perforations
- I/V pits large (13 - 50µ)
- Rays 1-8 seriate & homocellular to heterocellular
- Ray cells round as viewed on the tangential surface
- Crystals in Axial Parenchyma (chains of 1-5)
- “Gashes” in Latewood Vessels
WOOD SLIDES
Click on each image to view a
larger image.
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Cross-section of American
Black Walnut
(Juglans nigra)
showing growth ring boundary
and
reticulate parenchyma
in the latewood. |
Radial section of American
Black
Walnut (Juglans nigra)
showing a chain of crystals. |
Radial section of American
Black
Walnut (Juglans nigra)
showing “gashes”
in a
latewood vessel. |
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Radial section of American
Black Walnut
(Juglans nigra)
showing a close-up of “gashes”
in a latewood vessel. |
Radial section of American
Black
Walnut (Juglans nigra)
showing inter-vessel pits. |
Tangential section of American
Black
Walnut (Juglans nigra)
showing circular ray cells. |
  
CHARCOAL SLIDES
   
  
 
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