The white spruce of the South Dakotan Black Hills differs enough from its relatives that it is usually given its own varietal name. The cones are shorter, the needles a beautiful blue-grey, and the whole habit of the tree is tight and extremely attractive, which is why it is used in America as a Christmas tree and a garden ornamental.
The background of the Alberta spruce is a source of some disagreement. It is considered a south-western form of the white spruce (P. glauca), or perhaps as an intermediate form of a hybrid involving the Engelmann (P. engelmannii) and white spruces, which is what it undoubtedly looks like. The needles are longer than those of the typical white spruce, and the stems of the new growth are hairy, like the Engelmann.
The range of the white spruce covers the whole of the northern parts of North America, forming the tree-line together with black spruce (P. mariana) and tamarack (Larix laricina), aka eastern larch, American larch etc. It grows well on drier soils and on rich moraine soils. For paper and sawn timber it is one of the major species in the US, and THE major species in Canada. The crown resembles that of the Norway spruce but is denser and bluish in colour. The needles of some origins carry a strong scent.