Bur oak, Quercus macrocarpa, is the state tree of Iowa. How fitting then that we have planted oaks to honor the State's Governors and Lieutenant Governors! The collection is located in the southeast corner of the Arboretum just west of the Founders’ Grove. Governors, First Ladies, and Lieutenant Governors have dedicated many of these at Arbor Day celebrations. Some trees date to 1972 and are now reaching a respectable, if still juvenile, size. Several originated as transplants from the native 300-acre area across Peach Avenue. While this is our most concentrated planting of oaks, over two dozen species of oaks and oak hybrids are represented on the 40-acre site.