
The fir thrives on this north-exposed slope, called the ubac. Its needles have two white stripes on their undersides. They are arranged on either side of the boughs, and not all the way around them, which distinguishes it from the spruce. The elongated cones stand upright, rather than hanging downwards. They grow in large number, often mingling with larch trees under whose shade they can grow. By contrast, the larch - the "tree of light" - cannot grow under the cover of fir trees.