Spruce

Spruce — Spruce refers to trees of the genus Picea, a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal (taiga) regions of the earth. Spruces are large trees, from 20–60 (–95) m tall when mature, and can be distinguished by their whorled branches and conical form. The needles, or leaves, of spruce trees are attached singly to the branches in a spiral fashion, each needle on a small peg-like structure called a pulvinus. The needles are shed when 4–10 years old, leaving the branches rough with the retained pulvini (an easy means of distinguishing them from other similar genera, where the branches are fairly smooth).

Spruces are used as food plants by the larvae of some Lepidoptera species; see list of Lepidoptera that feed on spruces. They are also used as food plants by Gall Adelgids.

Spruce is one of the most important woods for paper manufacture, as it has long wood fibres which bind together to make strong paper. Spruces are cultivated over vast areas for this purpose.

Spruces are also popular ornamental trees in horticulture, admired for their evergreen, symmetrical narrow-conic growth habit. For the same reason, some (particularly Picea abies and P. omorika) are also extensively used as Christmas trees.

Spruce wood, often called whitewood, is used for many purposes, ranging from general construction work and crates to highly specialised uses in wooden aircraft and many musical instruments, including guitars, mandolins, cellos, violins, and the soundboard at the heart of a piano. The Wright Brothers first aircraft was built of spruce.