Family: Pinaceae, Pine view all from this family
Description Tree with very short needles crowded into mass suggesting a foxtail and a broad, irregular crown of spreading branches; a low shrub at timberline.
Height: 20-40' (6-12 m).
Diameter: 1-2 1/2' (0.3-0.8 m).
Needles: evergreen; 5 in bundle, with sheath shedding after first year; 3/4-1 1/2" (2-4 cm) long. Crowded in long, dense mass curved against twig; stout, stiff, blunt-pointed; persisting 10-20 years. Dark green, with white lines on inner surfaces; often with whitish resin dots on outer surface.
Bark: whitish-gray, smooth; becoming reddish-brown and furrowed into irregular, scaly ridges.
Cones: 2 1/2-3 1/2" (6-9 cm) long; cylindrical, dark purplish-brown, almost stalkless; opening at maturity; cone-scales 4-sided, with rounded bases and fine, slender, curved bristle; seeds brown mottled with black and with detachable wing.
Habitat Exposed, dry, rocky slopes and ridges of high mountains in subalpine zone to timberline; often in pure stands.
Range Utah to Nevada and E. California; at 7500-11,500' (2286-3505 m).
Discussion The oldest known dated living trees are Intermountain Bristlecone Pines more than 4,600 years old, protected at Inyo National Forest near Bishop, in eastern California. Other very old Intermountain Bristlecone Pines are found at Wheeler Peak Scenic Area, in the Humboldt National Forest of eastern Nevada. Although these trees are classed among the oldest known living things, some shrubs and trees that spread in colonies or clumps from the same root system may be older. The age of a tree is dated by counting the annual rings of wood produced by the cambium layer inside the bark. Wood cells formed in the spring are generally large, while those formed in the summer are smaller; the contrast in cell size from one year to the next is visible as a line. In an old Bristlecone Pine, small cores of wood are removed at different places around the trunk to locate the oldest ring in the center. Intermountain Bristlecone Pine used to be considered a variety of P. aristata.
