Black walnut trees are an integral part of any temperate deciduous hardwood forest. They can grow to a height of 100 feet, live up to 250 years and they are well known for their palatable nuts. They mainly grow in the Eastern United States in rich, moist soils. There are various types of walnut trees with identifiable characteristics. When identifying a tree look at the leaves, fruit, flower and bark.
We are going to take a look at a black walnut, and all the tools you can use to identify one, no matter the season:
Leaves: The leaves are compound, meaning they are composed of a main stem and many separate leaves, as shown below:
Fruit: The walnut is protected by a hard, round, shell. The fruit on a black walnut tree is green and turns blackish brown as it begins to ripen. The fruit grows in clusters and will fall during autumn. The shell contains a brown dye that will stain anything that comes in contact. It takes about 10 growing seasons for one tree to produce mature fruit!
Flower: The flower is a yellowish-green drooping catkin which covers the tree in the spring.
Bark: The bark has deep ridges that make a diamond like pattern and the color ranges from brown to dark gray.
The walnut is a beautiful tree to look at it, but it also has many uses.
The walnut is one of the healthiest nuts on earth and the wood is highly valued due to its color and durability. The fruit also provides a dye that is used to color fabrics and paper. In addition to these uses, the walnut shell, when grounded, can be used in cosmetics, pet litter, blast cleaning and paint stripping.
Interesting fact: Black walnuts are not toxic to humans, but they are toxic to horses. If a horse comes into contact with bark shavings or walnut fruit, they can develop a disease known as laminitis. Laminitis is an inflammation of the laminae (the soft tissues in the hoofs). When the laminae become inflamed the horse can suffer from damaged bones and other parts of the hoof.
Spot black walnuts in The Parklands:
We have a variety of trees at The Parklands, but the walnut tree is easy to spot this time of year. You can look for the broad, green fruits still hanging on the tree or spot some dark brown fruits laying on the ground. The above photo is of a black walnut that can be found in North Beckley Park, near William F. Miles Lakes. The lack of leaves and wealth of fruit makes the tree look like a christmas tree right now. Come out to The Parklands and see if you can spot this speciment and identify black walnut trees other places in the park!
Story by Olivia Kaiser – Interpretive Ranger for The Parklands.