The Spruce needle comes from source trees. Spruce trees are commonly mixed up with pine trees. Pine trees have a more smooth bark, spruce trees have a rougher textured bark. The bark on a spruce tree will become more scaly with age. Spruce trees are found in the Northern temperate and boreal regions. Spruce leafs are attached singly to the branches in spiral fashion. The needle shed when they are 4 to 10 years old. In this picture the palisade cells are visible and are filled with chlorophyll. The leaf vein isn't shown in this picture. The epidermis is there but hard to identify. the epidermis is the outermost layer which covers the whole plant structure.