Butternut
Juglans cinerea

Location in Ontario

Butternut (White Walnut) grows throughout the Deciduous Forest Region and further north. However, due to Butternut canker, many trees have died, making Butternut scarce today.
Butternut likes well-drained, rich soil.

COSEWIC (Committee on the Status of Endangered Wildlife in Canada) Status: Butternut is identified as a Endangered Species in Canada. This is due to loss of trees to Butternut Canker.

COSEWIC: Butternut


Large and small roadside Butternuts, Chatham-Kent
 

Genus Juglans
Walnuts as a genus have compound, alternate leaves with 11 to 23 leaflets. They are monoecious with male (pollen) flowers and female (seed) flowers on the same tree. Large, edible nuts are produced. The wood is treasured for the colour and grain. In Ontario, Black Walnut and Butternut (White Walnut) can be found. 

How Can You Tell Walnuts apart??
Black Walnut bark has dark furrows, Butternut is lighter with flat-topped ridges. Black Walnut leaves have smaller bottom leaflets, and the top leaflet is often missing. Butternut leaflets get narrower along the leaf. Walnuts are round, Butternuts are oblong and pointed.

In the Landscape
Butternut is a medium sized tree that grows up to 25 metres. It is short-lived to about 80 years. It makes a pretty landscape tree with attractive bark and compound leaves, however, it is risky to plant due to high risk of Butternut Canker. Healthy trees produce an abundant number of nuts.

TREE FACT: Butternut nuts can be boiled and the oil skimmed off to make a type of butter, hence the name "butternut".


Giant Butternut in flower, St. Williams Nursery and Ecology Centre

Leaves
Butternut has compound leaves, with 11 to 17 leaflets. Leaflets get narrower along the leaf. Leaves turn yellow in the fall.
Bark
The bark is light gray with narrow fissures and flat-topped ridges.
Flowers
Butternut is monoecious with male (pollen) flowers and female (seed) flowers on the same tree.  Pollen flowers are small and green, and found in long catkins. Seed flowers are in clusters at the end of a new shoot. Flowers appear in May with the leaves, and are wind pollinated.
Fruit
The fruit is an edible, hard nut with a green husk. Butternuts have sweet nuts, that are elongated spheres with pointed ends. Nuts are produced every 2 to 3 years after 20 years of growth.

Wood
Butternut wood is of medium hardness, much less than Black Walnut. It does have a nice grain, and has been used for furniture.
Specific gravity: 0.38
Janka Hardness: 490 lb

Wood Comparison Chart

Genetics
Butternut does not hybridize with Black Walnut, however it will hybridize with English and Japanese Walnut. Butternut is thought to have a haploid chromosome number of 16.


Butternut, Norfolk County

Link to United States Forest Service Silvics Manual for Butternut.

~~~~~