Limber pine

Appearance

''P. flexilis'' is found in the subalpine areas of the Rocky Mountains from southwest Alberta Canada south through Colorado and New Mexico into the northern states of Mexico; from mountains in the eastern Pacific Northwest states through the Great Basin states of Nevada and Utah. It is also found in California: in the Eastern Sierra Nevadas; the eastern California White Mountains; and the Southern California San Bernardino Mountains and San Gabriel Mountains of the Transverse Ranges. Continuing south the species is found in the San Jacinto Mountains, Santa Rosa Mountains, and Hot Springs Mountain of the Peninsular Ranges; and a small disjunct population in the Black Hills in South Dakota.

''P. flexilis'' is typically a high-elevation pine, often marking the tree line either on its own, or with whitebark pine , either of the bristlecone pines, or lodgepole pine . In favourable conditions, it makes a tree to 20-meter , rarely 25-meter tall. However, on exposed treeline sites, mature trees are much smaller, reaching heights of only 5-meter - 10-meter . In steeply-sloping, rocky, and windswept terrain in the Rocky Mountains of southern Alberta, limber pine is even more stunted, occurring in old stands where mature trees are consistently less than 3m in height.

Naming

''P. flexilis'' is a member of the white pine group, ''Pinus'' subgenus ''Strobus'', and like all members of that group, the leaves are in fascicles of five, with a deciduous sheath. This distinguishes it from the lodgepole pine, with two needles per fascicle, and the bristlecone pines, which share five needles per fascicle but have a semi-persistent sheath.