The pine, Pinus, is a resinous evergreen conifer of the northern world, keeping its green needles through the winter and living to great age. That constancy shaped its symbolism across Eurasia as a tree of endurance, longevity and steadfast integrity. In China the pine is foremost of the Three Friends of Winter, with the bamboo and the winter-flowering plum, a trio that stays green or blooms in the cold and stands together for the resilience and moral firmness of the cultivated person who keeps faith in hard times; the pine there is especially an emblem of long life and of the unbending upright character.
The pine family holds a genuine scientific record for tree longevity: the Great Basin bristlecone pine, Pinus longaeva, of the high mountains of California, Nevada and Utah, includes individually dated trees confirmed by tree-ring counts to be well over four thousand years old, among them a tree nicknamed Methuselah, making the species, by direct physical evidence rather than legend, among the oldest known living organisms on Earth and giving the pine's old symbolism of longevity an unusually solid factual foundation. The exact location of the oldest confirmed individuals is kept undisclosed by researchers to protect the trees from vandalism, a modern precaution for organisms that were already ancient when the pyramids of Egypt were built.