Swamp White Oak

Quercus bicolor

swamp_white_oak_leaf.jpg

Illustration of swamp white oak leaf.
Swamp white oak (Quercus bicolor) leaf.
Paul Nelson
Other Common Name
Swamp Oak
Family

Fagaceae (oaks)

Description

Swamp white oak is a medium-sized tree with an open, irregular, rounded crown, ascending upper branches, and pendulous lower branches.

Leaves are alternate, simple, 4–7 inches long, widest above the middle; margin with lobes or large, rounded teeth, or both, some of the side veins not ending in teeth; upper surface dark green, shiny; lower surface downy-whitish.

Bark is brownish; gray to dark brown with age; grooves deep, ridges broad, flattened, and loosely curling at the ends, appearing rough; bark on larger branches often peeling.

Twigs are stout, short, reddish-brown, smooth; older twigs with peeling bark.

Flowers April–May, in catkins.

Fruits September–October, acorns ¾–2½ inches long, in clusters of 1–3, on slender, dark stalks about 2½ inches long; nut light brown, about uniformly wide, about 1 inch long, tip pointed, hairy; cup covering to ½ the nut, light brown, with fine, woolly hair; scales flattened, sometimes with a short fringe on the border; seeds edible; ripen in the first year.

Size

Height: to 80 feet.

Swamp_White_Oak__MU_campus_10-18-17.jpg

Photo of a swamp white oak tree, grown in the open, showing overall tree shape
Swamp White Oak
Swamp white oak is a medium-sized tree with an open, irregular, rounded crown, ascending upper branches, and pendulous lower branches.

swamp_white_oak_acorn.jpg

Illustration of swamp white oak acorn.
Swamp White Oak Acorn
Swamp white oak (Quercus bicolor) acorn.

Oak _Quercus_spp_Flowers.jpg

Illustration of oak flowers and catkins, male and female.
Oak Flowers
All oak flowers are similar in appearance and emerge in early spring as the new leaves are expanding. Male and female flowers appear on the same tree.

Swamp_White_Oak_bark_MU_campus_10-18-17.jpg

Photo of the trunk of a mature swamp white oak tree
Swamp White Oak Bark
The bark of swamp white oak is brownish, turning gray to dark brown with age. The grooves are deep, and the ridges are broad, flattened, and loosely curling at the ends, appearing rough.

Swamp_White_Oak_acorn_MU_campus_10-18-17.jpg

Photo of a swamp white oak acorn, held in the palm of a hand
Swamp White Oak Acorn
Like most other oaks in the white oak group, swamp white oak produces edible acorns that ripen in their first year.

swamp_white_oak.jpg

swamp white oak
Swamp White Oak
Habitat and conservation

Occurs in moist bottomland forests in valleys and on rich, lower slopes, in wet ground bordering swamps and oxbow lakes of floodplain and stream meanders, and along streams. Despite its name, this species does not grow in swamps; instead, it lives in low, wet, sometimes poorly drained soils. This tree can live for 350 years; it begins to flower at 25–30 years of age. In cultivation, it can withstand drought conditions once established, though alkaline soils can cause undernourishment.

image of Swamp White Oak distribution map
Distribution in Missouri

Grows sparsely in the northern two-thirds of the state, but also found in the Ozarks. Most prevalent in our northeastern sections.

Status

The species name, bicolor (two-colored), refers to the contrasting colors on the two sides of each leaf, shiny dark green on the upper surface, whitish-fuzzy on the underside. Donald Culross Peattie said this oak "proclaims its . . . identity at a glance and at a distance. At least it does so if there is any free wind . . . , for on the slightest provocation this beauty among the Oaks shows its white flounced petticoats."

Human connections

A handsome shade tree, swamp white oak grows relatively quickly and can live for centuries. The wood is used for general construction, furniture, cabinets, veneer, interior finishes, fence posts, and fuel. The bicolored leaves flash white during the updrafts preceding summer storms.

Ecosystem connections

Many animals eat the plump, sweet acorns, including blue jay, woodpeckers, wood duck, wild turkey, ruffed grouse, bobwhite, mice, squirrels, raccoon, and white-tailed deer. Many of these animals scratch, pick, and poke at the forest floor all winter long for these acorns.