The term FIR refers to two types of trees, the SPRUCE and the PINE. Spruces are evergreen coniferous trees that belong to the genus Picea and have needle-like leaves. They are typically found in the Northern Hemisphere and can grow up to 80 feet tall. Pines are also evergreen coniferous trees that belong to the genus Pinus and have long needles in bundles of two, three, or five. They are also found in the Northern Hemisphere and can grow up to 100 feet tall. Both spruces and pines are important sources of timber and are used for a variety of purposes, including construction, furniture, and paper production.