SCIENTIFIC NAME: Pinus aristata
This tree in Colorado Bristlecone pine is native to Colorado. It is found in selected areas of the state and in urban landscapes. Naturally, it is found at higher elevations in the southern and central Rockies of our state. They are long-lived trees. In California, some are thought to be over 4000 years old. The oldest in Colorado is estimated to be over 2500 years. This species has a small but stout, irregular growth habit seldom reaching 25 feet. Needles persist on branches for many years giving it a “foxtail” look. Bristlecone is used in the landscape mostly as an accent type tree. Its dense, dark foliage gives it a strong look. It likes being in open, well-drained areas.
Hardiness Zone 3 to 7.
Growth rate Growth greatly depends on site. In landscaped, irrigated yards, growth can be 12″ per year. These trees can do well on rocky, poor sites with little or no irrigation.
Leaves and needlesThe needles of the bristlecone pine are in fascicles (bundles) of 5. They are densely crowded on branchlets, rigid, dark green, 1″ to 1 3/4″ long. Needles persist on branches for over 10 years. Sometimes as long as 17 years. This habit gives the branches a brushy look. Needles have spotty, white resin exudations.
Buds Nothing unusual. Small, covered with brown scales.
Cones Cones are sessile(not raised on a stalk), ovoid, 2″ to 4″ long by 1 1/2″ broad. There is a bristle-like prickle at the edge of each cone scale.
Bark Thin, smooth and grey-white on young stems. Furrowed and red-brown on older stems.
Insects and diseases Bark beetles, dwarf mistletoe, white pine blister rust.
Best advice Plant as a single species in a rock garden or other well-drained site. It is not a formal looking tree. It develops “character.” Can be trained as a bonsai.
Michael Dirr, Manual of Woody Landscape Plants (University of Georgia, 1990)
Michael Kuhns, Trees of Utah and the Intermountain West (Utah State University Press, 1998)
H.D. Harrington , Manual of the Plants of Colorado
Harlow & Harrar, Textbook of Dendrology