Thursday, July 24, 2008

Black walnut

What do walnuts, Wales, Walloon, Welsh, Walsh, Wallace, and Cornwall have in common? The words all indicate foreignness.

Walnuts are foreign nuts, and the "wal-" in their name indicates that fact. Foreign to whom? To the English. The American Heritage Dictionary explains the history nicely: "Although Celtic-speaking peoples were living in Britain before the arrival of the invaders...whose languages would eventually develop into English, it was the Celts and not the invaders who came to be called 'strangers' in English. Our words for one of the descendants of the Celtish peoples, Welsh, and for their homeland, Wales, come from the Old English word wealh, meaning 'stranger'.... Old English...walhhnutu [exists] in a document from around 1050.... This eventually became walnut in English...literally the 'foreign nut.' The nut was 'foreign' because it was native to Roman Gaul and Italy."(1)

Black walnut (Juglans nigra) is an American native closely related to the Persian walnut (Juglans regia) of Europe and Asia. It grows wild in the eastern United States except for parts of New York and New England.(2) The tree is highly valued for its wood and for its nuts. The wood is so valuable that black walnuts are at risk of being felled and stolen by "walnut rustlers." For that reason, I won't specify the locations of the pictured Plainfield trees. Walnuts have been prized since ancient times. The Romans esteemed them highly enough to call them Jupiter's nut (Jovis glans) from which the scientific name Juglans derives.(3)

Walnuts have pinnately compound leaves (with leaflets arranged like a feather), each leaf a foot or two in length and made up of as many as 23 leaflets. The leaflets are serrated, and the leaflet at the tip of the leaf is often undersized or missing, a useful feature in identification. The leaves emit a spicy odor when crushed. They turn yellow in the autumn and are among the earliest leaves to fall.

The bark is dark gray-brown and deeply furrowed, forming diamond shapes.

The nuts fall around the same time as the leaves and are covered by a fleshy green hull that will stain your hands black if you try to remove it. Breeders have produced over 500 varieties of black walnut, trying to create nuts with a thinner shell and a less convoluted inner structure so that the kernel is easier to extract.

Almost as well-known as its delicious nuts and its beautiful wood is walnut's toxic effect on neighboring plants. This effect has been known for millennia. Pliny the Elder wrote in the first century AD that, "the shadow of walnut trees is poison to all plants within its compass." Juglone, the toxin that the tree produces to keep the rest of the natural world at bay, is present in leaves, branches, bark, roots, and nuts. The chemical is toxic to a variety of other plants. Don't, for example, plant tomatoes near a walnut tree. The toxin's victims are not limited to plants. Bruised walnut leaves and branches have been put into water by fishermen to stun fishes.

(1) The American Heritage Dictionary of the English Language, Houghton Mifflin Company 2000. See the entry for Wales.

(2) Edward Goodell, Walnuts for the Northeast, Arnoldia 44: 1-19, 1984.

(3) The Romans' walnut was Juglans regia, Persian walnut. It is also called English walnut. But, as discussed above, there really is no such thing as an English walnut.

Copyright Gregory Palermo


charles L'Heureux said...


Really interesting article.

Especially the original meaning of the word WAL-nut.

Patti Mobus/Snover said...

My name is Patti Mobus/Snover. I was raised on Leland Ave, by Cook School.
I am now in Florida; however, keep in touch with Plainfield via friends who are still there. If anyone asks, there is a history as to why that tree was planted at Skillman gardens.
I don't remember who the property belonged to, however, there was an oriental type dwelling built there with a bridge across the creek. I remember lovely gardens and a peaceful feeling every time we went by there. I was young and I remember being horrified when they destroyed it to build those apartments there. The bridge was still there the last time I went by!