“Bur Oak has thick, corky bark which provides it with fire resistance…”– Fun Facts
Full Tree, Quercus macrocarpa (Ayotte, n.d.)
First described by Andre Michaux (1801) under the name Quercus macrocarpa, it is known as such to this day. There are two infraspecies, Quercus macrocarpa var. depressa and var. macrocarpa – but their acceptance varies between botanists and major taxonomic databases (Deitshmann, 1965; POWO, 2024; Tropicos, 2024).
Quercus macrocarpa can be distinguished from Quercus rubra, another Oak species in the park, by its acorns: Q. macrocarpa has a fringed cap that covers more than half the nut, whereas Q. rubra has a cap that is not fringed and covers much less than half the nut.
Quercus macrocarpa is the only oak species native to Montana (Nixon et al, 1997).
Bur Oak has thick, corky bark which provides it with fire resistance, enabling it to grow in savanna and open woodlands where periodic fire is common (Hengst & Dawson, 1994.)
Native
Introduced
Commonly found in open woodland areas on both dry hillsides, grasslands and savannas, and wetter lowlands (Morton Arboretum, 2024). Quercus macrocarpa grows naturally in multiple different climates and habitats from the east coast to as far west as Wyoming (Welsh et al, 2003). It is highly drought-tolerant.
According to the IUCN redlist, Quercus macrocarpa is labeled as ‘least concern’ but is noted as decreasing (Kenny & Wenzell, 2015).
