A Christmas tree is a decorated tree, usually an evergreen conifer, such as a spruce, pine or fir, or an artificial tree of similar appearance, associated with the celebration of Christmas.
Christmas tree decorated with lights, stars, and glass balls
Glade jul by Viggo Johansen (1891)
Typical North American family decorating Christmas tree (c. 1970s)
Martin Luther is depicted with his family and friends in front of a Christmas tree on Christmas Eve
A spruce is a tree of the genus Picea, a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. Picea is the sole genus in the subfamily Piceoideae. Spruces are large trees, from about 20 to 60 m tall when mature, and have whorled branches and conical form.
Spruce
The peg-like base of the needles, or pulvinus, in Norway spruce (Picea abies)
Pulvini remain after the needles fall (white spruce, Picea glauca)
Manually decorticated trunk of a spruce as protection against bark beetles