What's the world's most long-living tree?
That title goes to the bristlecone pine in and around California. The oldest known living specimen, "Methuselah," is more than 4,700 years old.
It actually was younger than another known tree until 1964. In that year, a graduate student doing research on Ice Age glaciers cut down another bristlecone pine, "Prometheus," in Nevada. That one turned out to have been at least 4,862 years old at the time. Bristlecone pines in the area have since come under federal protection, and Methuselah's location is being kept a secret, to keep it from the ravages of vandals and tourists.
More information on these trees can be found in a fascinating article from the San Francisco Chronicle: Staying Alive: High in California's White Mountains grows the oldest living creature ever found. You might also check out our Plant Hall of Fame.