This cross-section of one of the largest American Elm trees in the United States is about 5 feet in diameter. The tree died in 2000 as a result of Dutch Elm Disease and was approximately 200 years old.
Each of the little arrowed-tabs points to an annular ring and denotes a corresponding event in US/World history. The tab closest to the pith marks the beginning of the American Civil War and so on.
After being introduced to the US, Dutch Elm Disease decimated 95% of the American Elm population. Ironically, Ash trees were often planted in their stead and are now falling victim to the Emerald Ash Borer, marking a common pattern in the fall of American timber to invasive species.
Interestingly, apparently 1 in 100,000 thousand elm trees are resistant to the disease, including the St. Croix Elm in the Twin Cities from which cultivars are being taken and are now propagated. May they thrive.