Whitebark pine

Description

Pinus albicaulis, known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine areas of the Sierra Nevada, Cascade Range, Pacific Coast Ranges, and Rocky Mountains. It shares the common name "creeping pine" with several other plants. The whitebark pine is typically the highest-elevation pine tree found in these mountain ranges and often marks the tree line. Thus, it is often found as krummholz, trees growing close to the ground that have been dwarfed by exposure. In more favorable conditions, the trees may grow to 29 meters (95 ft) in height. Whitebark pine is a member of the white pine group, the Pinus subgenus Strobus, and the section Strobus; like all members of this group, the leaves (needles) are in fascicles (bundles) of five with a deciduous sheath. This distinguishes whitebark pine and its relatives from the lodgepole pine (Pinus contorta), with two needles per fascicle, as well as the ponderosa pine (Pinus ponderosa) and Jeffrey pine (Pinus jeffreyi), which both have three needles per fascicle; all three of these species also have a persistent sheath at the base of each fascicle. Whitebark pine owes its name to the light gray bark of its young specimens. Distinguishing whitebark pine (Pinus albicaulis), from the related limber pine (Pinus flexilis), also a member of the white pine group, is much more difficult, and usually requires seed or pollen cones. In Pinus albicaulis, the seed-bearing female cones are 4–7 centimeters (1+1⁄2–3 in) long, dark purple when immature, and do not open on drying, but the scales easily break when they are removed by the Clark's nutcracker to harvest the seeds; rarely are there intact old cones in the litter beneath the trees. Its pollen cones are scarlet.