Idaho White Pine

Pinus monticola (PY-nus mon-TI-ko-la)

Family: Pinaceae Native Understory

Western white pine is a tall pyramidal evergreen conifer tree that has a conical crown with horizontal branches and matures to a height of 100 feet. The counterpart of the western white pine is the eastern white pine, and it may be difficult to distinguish between the two. The western white pine tends to have stiff, dense blue-green needles, four stomatal bands on the inner surface, and larger cones than the eastern white pine. This needled evergreen is native to the northern Rocky Mountains from British Columbia to Montana and is also found along the Pacific Coast through the Sierra Nevada and Central California. It is most often found in moist valleys to dry open sites. The genus name, Pinus, is the Latin name for pines. The species epithet, monticola, means "inhabiting the mountains". It grows best in full sun, moist, well-drained acidic soils. This evergreen is monoecious. The male cones are small, yellow, and cluster at the tips of the branches. The female cones appear on stalks at the tips of the upper branches and are larger, rounded, and yellowish-green to bright pink. Pollen is dispersed in late June and early July. The fruit cone may be solitary or in groups of 2 to 5 cones. They are large and, cylinder-like, and mature in the second season. Ripening occurs during August and September. During the warm weather, they may drip white resin. The seeds are eaten by birds as well as small mammals, and the foliage is enjoyed by deer and grouse. Small rodents eat the bark and wood, and the pine needles provide nesting materials. The western white pine is native to the Pacific Northwest and is highly susceptible to blister rust. In North Carolina, it may be best to consider planting its counterpart, the eastern white pine. Quick ID Hints: bark is gray, thin, smooth, and becomes furrowed with rectangular plates with age stems are pale reddish-brown and become purplish-brown or gray, smooth with age needles are 5 fascicles, 1.6 to 4 inches long, 0.04 inches wide, blue-green pollen cones 0.4 to 0.6 inches long and yellow seed cones mature in 2 years, 4 to 5 inches long, tannish-brown to yellowish seeds are 0.2 to 0.28 inches long, reddish-brown with a 0.8 to 1-inch longwing Insect, Diseases, and Other Plant Problems: The western white pine is susceptible to a very serious fungal disease known as blister rust which can kill the tree. A resistant strain is currently being developed. It is also susceptible to pole blight, needle blight, and fungi that affect the root system. Insect pests include bark beetles, mountain pine beetle, and red turpentine beetle. This tree is susceptible to wind damage. VIDEO created by Ryan Contreras for “Landscape Plant Materials I: Deciduous Hardwoods and Conifers or Landscape Plant Materials II: Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University More information on Pinus .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 60 attributes.