The blue spruce (Picea pungens), also commonly known as green spruce, white spruce, Colorado spruce, or Colorado blue spruce, is a species of spruce tree. It is native to North America, and is found in USDA growing zones 1 through 7. Its natural range extends from northern New Mexico through Colorado and Utah to Wyoming and into Alberta and British Columbia, but it has been widely introduced elsewhere and is used as an ornamental tree in many places far beyond its native range. The blue spruce has blue-green coloured needles and is a coniferous tree.