“Bristlecone Pine is a very long-lived tree, with some trees estimated at over 5,000 years old.”– Economic and Ethnobotanical Uses
Whole bristlecone pine tree (Mendoza, 2009)
Pinus aristata was described by George Engelmann (1862) under its current name. However, even Englemann was uncertain where to place it taxonomically, as he also once considered it to be a variety of Pinus balfouriana (var. aristata; Parry & Engelmann, 1862).
Bristlecone pine can be identified by needles that grow in a dense all-round pattern. The tree usually has a scraggly and twisted appearance, which contrasts the columnar appearance of most pines. It is very difficult to tell the difference between Pinus aristata and the Great Basin Bristlecone Pine found in Utah, Nevada, and California (Pinus longaeva). However, Pinus aristata has longer, sharper needles that are a darker green-blue and have a long narrow groove on the back and the cones have a long bristle that is 6-10 mm long, whereas P. longaeva’s needles are yellow-green and have cone bristles much shorter (1-6 mm) (Kral, 2020b).
Bristlecone Pine is a very long-lived tree, with some trees estimated at over 5,000 years old.
One individual contained more than 2,400 tree rings when a core was extracted to measure its age in 1992 (Brunstein, 1993). The size of tree rings indicates the stress a tree experienced in a year, providing a snapshot of the general conditions of the area for the last 2,400 years.
Pinus aristata is very slow growing.
Native
Introduced
Pinus aristata typically grows on steep slopes in high montane environs but can survive on level ground as long as it drains well. It thrives in areas that receive 34-45 inches of rain per year and tolerates cold climates above 10,000 feet elevation. They produce seed regularly, and many of their seeds are eaten by rodents (Fryer, 2004).
Pinus aristata is considered vulnerable overall and imperiled in Arizona (NatureServe, 2024). Its status may continue to decline as it was recently shown to be susceptible to the mountain pine beetle which can kill whole stands of trees (Bentz et al. 2021).
