Kansas Wildflowers and Grasses

SWAMP WHITE OAK

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Quercus bicolor Willd.

Dyck Arboretum, Harvey County, Kansas

Height: Trees, to 98 feet

Family: Fagaceae - Beech Family

Flowering Period: May

Trunks:

Erect; branches unarmed; bark light gray to grayish brown, fissures shallow, ridges flat, plates blocky, flat; wood light brown, dense.

Twigs:

Brown to grayish brown, rigid, somewhat brittle, glabrous or with scattered simple or branched hairs; leaf scars crescent-shaped to nearly hemispheric; buds brown to reddish brown, globose to ovoid, .08 to .12 inch, apex rounded to obtuse, glabrous or sparsely hairy, scales ciliate.

Leaves:

Deciduous, alternate, simple; stipules deciduous; petiole .4 to 1 inch, glabrate to sparsely hairy with branched hairs; blade obovate to narrowly elliptic in outline, 4.8 to 8.8 inches long, 2.8 to 5.6 inches wide, base cuneate to acute, margins shallowly (3-)5-8-lobed, -scalloped, or -toothed per side, sometimes lobed proximally and scalloped or toothed distally, lateral lobes oblong, spreading or projecting forward, sinuses extending 1/5-1/4 distance to midrib, lobe apex obtuse to rounded, not bristle-tipped, lower surface stellate-tomentose, grayish green or dull green, upper surface glabrate or sparsely stellate-hairy along veins, dull to shiny green.

Flowers:

Inflorescences staminate catkins at base of new growth, 25-35-flowered, pendent, 1.6 to 3.2 inches; peduncle .24 to .8 inch; pedicels absent; pistillate spikes axillary from new growth, 1-3(-5)-flowered; peduncle 1 to 2 inches; pedicels absent. Flowers unisexual, more or less radially symmetric; staminate flowers: sepals 2-6, connate, calyx lobes .05 to .06 inch; petals absent; stamens 5-7; pistillate flowers: sepals 6, connate, calyx fused to ovary; petals absent; pistil 1; styles 3.

Fruit:

September-October; acorns, maturing first year; peduncle elongating to .8 to 3 inches; cup hemispheric to top-shaped, .4 to .6 inch long, .6 to 1 inch long, enclosing 1/3 to 3/4 of nut, scale apices irregularly recurved; nut light brown, ellipsoid to ovoid, .8 to 1.2 inch long, .5 to .7 inch wide, glabrous; attachment scar .3 to .55 inch diam.; seed 1.

Habitat:

Floodplains, wet meadows, edges of swamps.

Distribution:

East 1/7 of Kansas

Origin:

Native

Comments:

There are historical reports of swamp white oak in extreme eastern Kansas in public land survey system records from the 1850s and 1860s. Swamp white oak was found to be common on the Marais des Cygnes National Wildlife Refuge in Linn County in 2004. Subsequent field and herbarium work revealed additional populations in Franklin, Johnson, and Miami Counties, all along the eastern border of the state. Swamp white oak is sometimes planted as a shade tree.

Swamp white oak staminate inflorescence