This bur oak (Quercus macrocarpa 'Eckman') is 24 years old, but barely taller than I am. It's a dwarf cultivar discovered in Barrington, Illinois, here grafted at the Morton Arboretum. By contrast, wild-type bur oaks we planted from seed at the Arb have grown to more than 10 feet tall in only 4 yrs.