It is difficult, under the snow, to distinguish spruce from fir trees since it is mainly by their needles that we differentiate them. The needles of the spruce are square in section (whereas they are flat in the fir) and distributed all around its twigs whereas they are arranged in only two rows in the fir and have two white stripes on their underside. As for the trunk, it is scaly and reddish for the spruce but smooth and silvery gray for the fir.