Editor's Picks
Plant Focus
The US National Champion Quercus robusta
I recently had the opportunity of visiting the US National Champion Quercus robusta, which grows on private property in Jeff Davis County, Texas. During the initial discussion with the ranch manager, when he mentioned visiting the champion tree, I assumed he misspoke and meant Q. rugosa, as I was unaware of any collections of Q. robusta in Jeff Davis County but quite familiar with the population in the Chisos Mountains—trees I have visited many times over the years. As we approached the grove, and still expecting to see Q. rugosa, I was surprised to see what appeared to be Q. robusta. My confusion quickly subsided as we walked up to the tree. I inspected a few of the leaves that remained on the tree from last year; the size and appearance resembled the leaves of the trees I was familiar with 100 miles south in the Chisos Mountains. Overall, the tree was in good health. All the upper and outward branches were leafing out, and the tree was flowering. There were a few dead lower branches, but nothing concerning, and fully expected on a tree this size.

According to the Texas Big Tree Registry, this tree was nominated, measured, and certified in 2017, and I imagine that someone from the Texas Forest Service would have verified the species. The data in the Registry is also published in American Forests’ Official Register of Champion Trees:
Trunk Circumference: 119 inches (3.02 m, i.e., DBH = 1.12 m)
Height: 54 feet (16.5 m)
Crown Spread: 74 feet (22.6 m)
Total Points: 192
These dimensions are similar to but certainly larger than those mentioned by C.H. Muller in the original description of the species:
“A large tree with low, wide spreading main branches, stiff young branches, and dark grey or black bark roughly furrowed, the trunk as large as 1 m in diameter, the crown about 10 to 12 m high and about 15 m broad.”

Further reading
Beckman, E., A. McNeil-Marshall, S.M. Still, A. Meyer, and M. Westwood. 2019. Quercus robusta C.H.Müll. In Beckman, E., A. Meyer, G. Man, D. Pivorunas, A. Denvir, D, Gill, K, Shaw, K. and M. Westwood. Conservation Gap Analysis of Native U.S. Oaks (pp. 184-189). Lisle, IL: The Morton Arboretum. https://mortonarb.org/app/uploads/2021/08/species-profile-quercus-robusta.pdf
Jensen, R.J. 1997. Quercus robusta in Flora of North America Editorial Committee Flora of North America North of Mexico 3, Oxford University Press, New York and Oxford. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501078
Mueller, C.H. 1934. Some new oaks from Western Texas.Torreya 34: 119–122. https://www.biodiversitylibrary.org/page/32129381#page/151/mode/1up