There are three closely related species of bristlecone pines:
Great Basin bristlecone pine (Pinus longaeva) in Utah, Nevada and eastern California.
The famous longest-lived species; often the term bristlecone pine refers to this tree in particular.

Rocky Mountain bristlecone pine (Pinus aristata) in Colorado, New Mexico and Arizona.
The most populous species; capable of forming closed canopies and, unlike the other two, is commonly cultivated.

Foxtail pine (Pinus balfouriana) with two disjunct populations found in the Klamath Mountains (subspecies balfouriana) and the southern Sierra Nevada (subspecies austrina).
A small outlying population was reported in southern Oregon, but was proven to have been misidentified.
Forms the thickest groves of the three.

At least some of the three species can hybridize in cultivation, but the ranges of wild populations do not overlap.
The Colorado River and Green River produce a 160-mile (260 km) gap between the ranges of P. longaeva and P. aristata and the northern Owens Valley provides a 20-mile (30 km) gap between the ranges of P. longaeva and P. balfouriana.
There are three closely related species of bristlecone pines:
Great Basin bristlecone pine (Pinus longaeva) in Utah, Nevada and eastern California. The famous longest-lived species; often the term bristlecone pine refers to this tree in particular.
Rocky Mountain bristlecone pine (Pinus aristata) in Colorado, New Mexico and Arizona. The most populous species; capable of forming closed canopies and, unlike the other two, is commonly cultivated.
Foxtail pine (Pinus balfouriana) with two disjunct populations found in the Klamath Mountains (subspecies balfouriana) and the southern Sierra Nevada (subspecies austrina). A small outlying population was reported in southern Oregon, but was proven to have been misidentified. Forms the thickest groves of the three.
At least some of the three species can hybridize in cultivation, but the ranges of wild populations do not overlap. The Colorado River and Green River produce a 160-mile (260 km) gap between the ranges of P. longaeva and P. aristata and the northern Owens Valley provides a 20-mile (30 km) gap between the ranges of P. longaeva and P. balfouriana.
Bristlecone pine