List of oldest trees

Cross-dating via dendrochronology is the most exact method for dating a wood sample. Cross-dating is the method of finding the age of a tree ring by matching growth patterns across multiple trees from the same location. Cross-dating can date a wood sample to a precision of one year. This list contains tree ages determined from dendrochronological cross-dating. It has all trees with ages more than 2000 years, and a sample of notable trees (one per species) younger than that. If cross-dating has not been reproducible (e.g., because a tree core has become missing), the unreproduced age is listed in the section below. If there are multiple ages (e.g., due to inconsistency in tree cores or lack of reproducibility), the lowest verified age is shown here, and the highest is shown in the estimated table, below. ==Non-clonal trees with estimated ages==

Note: The ages of the trees in this list are estimated via methods that are less accurate than cross-dating. Some of the ages are based on tree size, which is known to have 20% error. Ages in this table should be treated as speculative. ==Clonal trees==

As with all long-lived plant and fungal species, no individual part of a clonal colony is alive (in the sense of active metabolism) for more than a very small fraction of the life of the entire clone. Some clonal colonies may be fully connected via their root systems, while most are not actually interconnected, but are genetically identical clones which populated an area through vegetative reproduction. Ages for clonal colonies, often based on current growth rates, are estimates. ==See also==