Walnut is a common hardwood in North America. The two main types of walnut are English walnut and black walnut. Related to the black walnut are Claro Walnut and one or two hybrid walnuts.
When a North American speaks of walnut wood, the wood usually referred to is black walnut. Blank walnut trees grow quickly and sprout easily from seed. Once established, they can prevent other types of plant growth. There is some speculation that they can be poisonous to horses.
The most marked characteristic of black walnut is its dark color. Its grain is typically straight and of medium size, and it is an open-grained wood. Occasionally a walnut burl can be found.
Walnut responds to oil finishes by darkening markedly.