is a specific kind of: nut tree.

is a broader term that covers: California black walnut, Juglans californica | butternut, butternut tree, Juglans cinerea, white walnut | black hickory, black walnut, black walnut tree, Juglans nigra | Circassian walnut, English walnut, English walnut tree, Juglans regia, Persian walnut.

has as a part: walnut.

is a member of: genus Juglans, Juglans.

contains: walnut.