Where Found
The tree grows best around stream banks, roadsides and in rich soil with good drainage, but is in decline because of butternut canker, caused by a fungus. It's especially threatened and vulnerable in Kentucky, New York and Tennessee.
Butternut is considered a hardwood, because it's an angiosperm, which means it is a flowering seed-producing plant. Softwoods are gymnosperms, which means their seeds develop on the surface of cones or stalks, like conifers and ginkgoes.
Butternut wood takes about a month to dry out after it's cut and doesn't shrink very much.
Heartwood
The heartwood of butternut is dark medium brown, but not as dark as black American walnut. It has a straight grain, which means its fibers run parallel to the main axis of the tree. It weighs around 28 lbs. per cubic foot. It's also less strong than black walnut, but is much softer and easier to work with. The tree's annual rings form beautiful patterns.
Uses
Woodworkers use butternut for utility joinery, interior trim for boats, cabinet knobs, handles and pulls and furniture crates and boxes. It's good for carving and for decorative veneer. You can substitute it for black walnut. One problem is the wood is so soft that you need to keep cutting tools, whether manual or power tools, very sharp. The wood is good for nailing, screwing and gluing, takes stains well and is highly polishable.
Vulnerabilities
Butternut isn't a long lived tree -- it rarely lives to 80 years old -- and its timber isn't very durable. Besides the butternut canker the wood is subject to attack by the furniture beetle. Preservative isn't as effective on butternut as it is on other woods, even though the sapwood can be penetrated.