First most the mass of a tree is not living, consisting of dead cells. Secondly many plants reproduce vegetatively so that a grove of aspens or a field of goldenrods may actually be a single organism connected by underground roots. The Mendocino Tree in the Montgomery Woods State Preserve of California is 336 feet tall. Not everyone agrees that the Redwood has the tallest tree. Some claim that there have historically been taller specimens of Douglas Fir and a few claims for eucalypts in Australia have been made.
Sequoias can also be very old.
Trees with estimated ages of over 2200 years are known. Redwoods form magnificent forests along the Pacific Coast of northern and central California. Trees more than 4600 years old have been found in Inyo National Forest near Bishop, California. Intermountain Bristlecone Pine occurs at high elevations in the mountains of east-central California, Nevada, and Utah. The species occurs at very high elevations in the subalpine to timberline zones on exposed and dry rocky slopes and ridges.