The bristlecone pines are three species of pine trees (family Pinaceae, genus Pinus, subsection Balfourianae) that are thought to reach an age far greater than that of any other single living organism known, up to nearly 5,000 years. Bristlecones grow in scattered subalpine groves at high altitude in arid regions of the Western United States. The name comes from the prickles on the female cones.