<Tr> <Td_colspan="2"> <P> About 35; see text . </P> </Td> </Tr> <P> About 35; see text . </P> <P> A spruce is a tree of the genus Picea / paɪˈsiːə /, 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 about 20--60 m (about 60--200 ft) tall when mature, and can be distinguished by their whorled branches and conical form . The needles, or leaves, of spruces are attached singly to the branches in a spiral fashion, each needle on a small, peg - like structure . The needles are shed when 4--10 years old, leaving the branches rough with the retained pegs (an easy means of distinguishing them from other similar genera, where the branches are fairly smooth). </P> <P> Spruce are used as food plants by the larvae of some Lepidoptera (moth and butterfly) species, such as the eastern spruce budworm . They are also used by the larvae of gall adelgids (Adelges species). </P>

How many different types of spruce trees are there