Bur Oak

Bur oak, Quercus macrocarpa (estimated to be over 200 years old)

Another member of the white oak subgenus, bur oak can be found throughout a large portion of the Great Plains, parts of the eastern United States, and along the southern edges of Canada. While bur oak is the most common name, others include blue oak, mossy white oak, scrub oak, and mossycup oak. Compared to all other native oaks, bur oak has the largest acorns, is also one of the most drought resistant, and is also one of the most cold tolerant of the natives.

Bark of the Bur Oak.

Although bur oak is a slow growing tree, it can reach impressive sizes and live a long life. On average, a mature tree may reach up to 30 m (100 ft), but many grow beyond that with one region recording bur oaks averaging 52 m (170 ft) tall in the Ohio Valley. They also average a lifespan of 200 to 300 years, but may also easily surpass the average. They are a preferred browse for deer and rabbits, especially when young and in reach. The acorns are also a common food source for many wildlife species including squirrels and raccoons, and when at maturity, a common nesting and roosting sight for numerous bird species.

The above bur oak is estimated to be over 200 years old. It has been home to owls, carpenter ants, bee hives, and numerous other wildlife over the years. Although located in a floodplain where water can easily reach 1 m (3 ft) in depth, it has thrive and crayfish often then create homes around it. This bur oak as well as a few other old, mature ones can be found at the Heard Natural Science Museum and Wildlife Sanctuary.