Butternut

Native to eastern North America.

• Distributed from New Brunswick and southern Quebec west to Minnesota and South Dakota, south to Arkansas, Alabama, and Georgia
• Most abundant in New England, the Great Lakes states, and the St. Lawrence River Valley
• Found at elevations from sea level to approximately 1,000 meters
• A component of rich, moist deciduous forests, often found along streams and on lower slopes
• The species name "cinerea" means "ash-gray" in Latin, referring to the fuzzy, grayish young twigs
• Native American peoples used the nuts extensively for food and the husks for dye and medicine
• Butternut was an important food source for early European settlers in North America
• During the American Civil War, the Confederate soldiers from the backwoods were sometimes called "Butternuts" because of the butternut-dyed homespun uniforms they wore
• The butternut is the state tree symbol of South Dakota

A medium-sized deciduous tree with a broad, spreading, open crown.

Bark:
• Light gray, developing wide, flat, horizontal ridges with age
• The bark pattern is distinctly different from the deep, interlacing fissures of Black Walnut
• Inner bark is bright yellow and mildly staining

Leaves:
• Alternate, pinnately compound, 30 to 60 cm long with 11 to 17 leaflets
• Leaflets lanceolate, 5 to 10 cm long, finely serrated
• Lighter green and softer-textured than Black Walnut leaves
• Turn pale yellow in autumn

Flowers:
• Monoecious — male and female flowers on the same tree
• Male flowers in dangling green catkins, 5 to 10 cm long
• Female flowers in small terminal spikes of 3 to 5
• Wind-pollinated in late spring

Fruit:
• Elongated, cylindrical nuts, 3 to 6 cm long
• Enclosed in a sticky, hairy, green husk that does not turn black like Black Walnut
• Husk is densely covered in sticky, glandular hairs
• Shell is deeply ridged and extremely hard
• Kernel is rich, sweet, buttery, and oily — considered sweeter than Black Walnut

Form:
• 15 to 25 meters tall with trunk diameters of 30 to 70 cm
• Crown broad, spreading, open, and somewhat irregular
• Less formal in appearance than Black Walnut

The Butternut is an important but declining component of eastern North American forests.

Habitat:
• Found in rich, moist, well-drained deciduous forests, along streams, and on lower slopes
• Prefers deep, fertile, loamy soils
• Often found in disturbed sites, forest edges, and fence rows
• Less shade-tolerant than many other forest trees

Ecological interactions:
• Nuts are an important food source for squirrels, chipmunks, and other small mammals
• Also consumed by wild turkeys, woodpeckers, and blue jays
• Host plant for Luna Moth and other caterpillar species
• Produces juglone, though less aggressively than Black Walnut

Growth:
• Moderate growth rate of 30 to 50 cm per year
• Shorter-lived than Black Walnut, typically 75 to 100 years
• Sprouts from stumps when damaged
• Deep taproot makes it wind-firm

The Butternut is one of the most critically threatened tree species in eastern North America.

Conservation status:
• Listed as Endangered in Canada (COSEWIC)
• Ranked as Vulnerable or Imperiled across much of its US range
• An estimated 80% of mature Butternuts have been killed by Butternut Canker Disease

Threats:
• Butternut Canker Disease (Ophiognomonia clavigignenti-juglandacearum) — a fungal pathogen first identified in the 1960s, though believed to have been present earlier
• The disease creates dark, sunken cankers on branches and trunks, eventually girdling and killing the tree
• Origin of the pathogen is uncertain — may be an introduced species
• No effective treatment exists for infected trees

Conservation efforts:
• The US Forest Service and Canadian Forest Service are screening surviving trees for natural resistance
• Some apparently resistant individuals have been identified and are being propagated
• Grafting programs preserve genetic diversity of resistant trees
• Planting of resistant stock is encouraged on appropriate sites
• Hybridization with Japanese Walnut (Juglans ailantifolia) produces "buartnut" with some canker resistance

A beautiful but imperiled native tree — plant resistant stock when available.

Site selection:
• Full sun to light shade
• Deep, fertile, well-drained loamy soils
• Not suitable near juglone-sensitive gardens
• Best in naturalized settings and woodlands

Planting:
• Plant seedlings from verified canker-resistant parent trees when possible
• Plant in spring after frost danger passes
• Container-grown seedlings transplant more successfully than bare-root

Care:
• Water during dry periods for the first few years
• Monitor for canker symptoms — sunken, dark lesions on bark
• Prune out infected branches immediately to slow disease progression
• Report any apparently resistant trees to local forestry authorities
• Hardy in USDA zones 3 to 7

The Butternut has been valued for its sweet nuts, beautiful wood, and versatile dye.

Edible nuts:
• Kernels are sweeter, oilier, and more buttery than Black Walnut
• Used in baking, candy-making, and as a table nut
• Highly prized by those who can find them, as commercial production has nearly ceased
• Native Americans pressed the nuts for their rich oil

Wood:
• Lighter, softer, and warmer in color than Black Walnut — pale golden-brown
• Takes a beautiful satiny finish — used for furniture, interior trim, and decorative veneer
• Historically used for carving, toy-making, and church altars
• Less commercially valuable than Black Walnut but highly regarded by woodworkers

Dye:
• Husks and bark produce a rich yellow-orange to brown dye
• Used by Native Americans and colonists for dyeing cloth, baskets, and leather
• Confederate soldiers' homespun uniforms were dyed with butternut husks

Traditional medicine:
• Bark used as a mild laxative and tonic
• Husk preparations used as an antifungal and for skin conditions