PINES—Three species.—They have their needles gathered together at the base in bundles of from two to five. The cones are woody and pendent.
Limber pine (Pinus flexilis).—Stout, dark-green needles, 1½ to 3 inches long, in bundles of five. Cones 3 to 10 inches long, with seeds about ⅓-inch in length. Cone scales smooth. Bark light gray, except on old trunks, which are blackish brown and furrowed.
Ponderosa pine (Pinus ponderosa).—This tree was formerly known as western yellow pine. Needles 5 to 11 inches long, dark green, usually three in a cluster, but often in twos and in tufts at the ends of the branches. Cones 3 to 6 inches long, oval-shaped. Cone scales armed with spines. When young, the bark is dark, and the tree is known as “black jack” or “bull pine.” When older, the bark is reddish brown and occurs in thick, scaly ridges.
Piñon or piñon pine (Pinus edulis).—Piñon is a short, scrubby tree, often growing in mixture with juniper, and is confined to the foothills. Needles usually in bundles of two, rarely three, ¾ to 1½ inches long. Cones 1½ inches long and almost as broad, containing large seeds, which are the piñon nuts of commerce.
SPRUCES.—Two species. Needles scattered over the twigs singly. Needles are sharp-pointed, four-sided, leaving twigs rough like a grater when they fall off. Cones pendent, with parchmentlike scales, falling off the tree whole.
Engelmann spruce (Picea engelmannii).—The new-growth twigs are covered with soft, short hairs. Needles less rigid and less sharply pointed than those of blue spruce; green, dark blue green, or pale steel blue. Cones about 2 inches long. Bark is dark reddish brown and separates in the form of small, rounded scales. Main trunk, in contrast to blue spruce, is smooth and clean.
Blue spruce (Picea pungens).—The new-growth twigs are not covered with hair. Needles stiff, with sharp points, varying in color from silvery blue to green. Cones about 3 inches long. Bark of mature trunks gray and deeply furrowed. Main trunk always has numerous short twigs pushing out between branches.
FIRS.—Two species. Needles blunt, flat, and soft to touch, without any stem where they join branches. Needles leave flat, round scars when they fall off, in contrast to short stubs left by spruce needles on twigs. Cones, unlike those of other conifers, are erect. In the fall the cone scales drop off, leaving only a spike on the branch. Buds blunt and pitchy. Blisters containing pitch or balsam are scattered over the smoother bark.
Alpine fir (Abies lasiocarpa).—Blunt flat needles, about 1 to 1¾ inches long, soft to the touch and fragrant. Needles tend to turn upward. Dark-purple cones, 2¼ to 4 inches long. Bark smooth, grayish white, except on older part of the trunk, where it is broken into ridges. Tree has a sharp, spirelike crown. Grows at high altitudes, usually with Engelmann spruce.
Corkbark fir (Abies arizonica).—The trunk, crown, cones, and needles of the corkbark and alpine fir are so alike in general appearance that the two cannot be readily distinguished by these features. The cone scales of the corkbark fir are of a different form than those of the alpine, and the bracts borne on the backs of the scales also differ materially. The ashy-gray, soft, corky trunk bark alone readily distinguishes this tree from the alpine fir.