Home » Compare Plants

Swamp White Oak vs Bur Oak

Bur oak and swamp white oak are very similar and can occupy the same habitat, especially in the Midwest where both are common. However, certain key characteristics of bark, leaf shape, and acorns can usually distinguish them. These two species can hybridize and possibly form intergrades. Hybrids have been recorded in the wild in much of the area where these species overlap, and they can be locally common.

Swamp White Oak (Quercus bicolor)

Bur Oak (Quercus macrocarpa)

A large white oak favoring wet habitats.
A rugged oak native to North America, with a wide distribution, ranging farther west and north than most oaks that also occur in the east.
Bark peels on young branches.
Photo © , CC BY-SA 4.0.
Bark forms rugged ridges on young branches.
Photo © Christian Grenier, Public Domain.
Scales close to the tip of the acorn cap have shorter tips. Some scales farther back on the cap may have longer tips. Cap covers 1/3rd to 1/2 the acorn.
Photo © luka.r.s (Flickr), CC BY-SA 4.0.
Scales at the edge of acorn cap have elongated tips which curl backwards, creating a "mossy" appearance. Cup covers 1/2 or more of the acorn.
Photo © Lisa Winnett-Pequeno, CC BY 4.0.
Side veins are usually straighter, with most remaining at a 45° angle to the leaf midrib.
Photo © , CC BY-SA 4.0.
Side veins from the leaf's halfway point and closer to the base, often curve outward, with some curving as far as to point perpendicular to the midrib as they approach the leaf margin.
Photo © askalotl, Public Domain.