Picea

A spruce is a tree of the genus Picea, a genus of some 37 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Northern Hemisphere. Picea is treated either in the subfamily Pinoideae, or the sole genus in its own subfamily Piceoideae. Spruces can be distinguished from other genera of the family Pinaceae by their needles (leaves), which are four-sided and attached singly to small persistent peg-like structures (pulvini) on the twigs. The needles are shed when 4–10 years old, leaving the twigs rough with the retained pegs. Pests of spruce forestry include green spruce aphid, eastern spruce budworm, European spruce bark beetle, and great spruce bark beetle. Spruce is a major producer of timber for construction, and of pulp for paper. It is the standard material for the soundboards of stringed instruments like acoustic guitars. Native Americans use the roots of some species for weaving baskets. The Norway spruce is widely used for Christmas trees. Artists including Augustin Hirschvogel in the 16th century, Edvard Munch around 1900, and Eija-Liisa Ahtila in the 21st century have depicted spruces in etchings, oil paintings, and video installations.