Juglans cinerea | Juglandaceae

Submission: Shriver Hansen and Heidi Nydam

Identification:

Leaves – Odd-pinnately compound with 11-17 oblong-lanceolate leaflets.

Twigs and Buds – Stout, with a dark brown chambered pith. The leaf scar is truncate with a dense hairy pad on top and 3 u-shaped bundle scars. The terminal bud is flattened, with a few pubescent scales and lateral buds often superposed.

Fruit – 2” in length and edible. It has an oblong-ovoid shape with a husk covered with sticky pubescence. The nut itself is deeply corrugated with sharp ridges.

Bark – Light gray and divided by fissures into broad, often interlacing ridges.

Natural History:

The butternut (Juglans cinerea), a member of the walnut family, is a medium-sized tree, which can reach heights of up to 60 feet. Due to its role as a short-lived pioneer persisting for typically only 75 years, it is often found along cleared areas such as roads and fences in moist, well-drained sites. While originally native to much of Eastern Canada and the Central and Eastern United States, its range and frequency within that area are declining. It is now classified as endangered in some states, in part due to a fungal disease. 

In the past 50-60 years, butternut has been plagued by an aggressive canker disease that has drastically reduced its populations. This infection, caused by the fungus Sirococcus clavigignenti-juglandacearum and spread primarily by rain, causes a degradation of the wood and eventually kills the tree when individual cankers group together and prevent the movement of resources throughout the tree. Unfortunately, there is no known cure for the disease once an individual is infected.

Before its recent decline, the butternut held significant importance for indigenous people in what is now the Northeastern US. Indigenous peoples used its bark, roots, and husks to create medicine, generously sharing with early European settlers. They also threw the toxic bark into streams to fish, toxifying the water and stunning the fish. The nuts served as a good dietary source of fat and protein. Contemporarily, the sweet nuts are used in baked goods and for making maple-butternut candy. One of its primary uses has been in the creation of a gray dye, indicated by the presence of the Latin adjective cinerea in its scientific name, translating simply as “ashen” or “gray”. This dye, among dyes made from other plants, was used to color the gray uniforms of the Confederate Army during the Civil War. Today, butternut wood is sought after for its grain and finish as veneer for furniture and other woodworking. It is moderately hard, but quite workable, as it saws and carves easily.

Similar to other species of the Juglans genera, butternut produces a chemical substance known as juglone, which enters the environment through volatilization within the leaves, leachate from decomposing matter, and exudation from roots. The highest concentrations are found in the roots, nut hulls, and buds, while leaves and stems have lower levels. Juglone prevents the growth and survival of nearby plants by hindering seed germination, growth rate, photosynthetic ability, and reproduction. This leads butternut and its relatives to have a wide berth devoid of other plant life, which often extends to their drip line, or outermost edges of their canopy’s reach. Therefore, they are classified as allelopathic. So, despite this tree’s beauty and interestingly shaped compound leaves, planting it in gardens or other cultivated areas where one might hope for other plant growth is not recommended. 

References:

Kuhajda, N. 12 February 2021. Eliminating the Competition…Allelopathy in Plants. University 

of Illinois Urbana Champaign.

Lewis CT, Charles C. 1879. A Latin Dictionary. Oxford: Clarendon Press.

Shane, J. 2004. Dendrology Handbook, University of Vermont, Unpublished.

Woeste K, Pijut PM. 2009. The Peril and Potential of Butternut. Arnoldia. Vol 66, No. 4.