Bur Oak Over-cup Oak Mossy-cup Oak
=Habitat and Range.=--Deep, rich soil; river valleys.
Nova Scotia to Manitoba, not attaining in this region the size of
the white oak, nor covering as large areas.
Maine,--known only in the valleys of the middle Penobscot (Orono)
and the Kennebec (Winslow, Waterville); Vermont,--lowlands
about Lake Champlain, especially in Addison county, not common;
Massachusetts,--valley of the Ware river (Worcester county), Stockbridge
and towns south along the Housatonic river (Berkshire county); Rhode
Island,--no station reported; Connecticut,--probably introduced in
central and eastern sections, possibly native near the northern border.
South to Pennsylvania and Tennessee; west to Montana, Nebraska,
Kansas, Indian territory, and Texas.
=Habit.=--A medium-sized tree, 40-60 feet high, with a trunk diameter of
1-3 feet; attaining great size in the Ohio and Mississippi river basins;
trunk erect, branches often changing direction, ascending, save the
lowest, which are often nearly horizontal; branchlets numerous, on the
lowest branches often declined or drooping; head wide-spreading, rounded
near the center, very rough in aspect; distinguished in summer by the
luxuriance of the dark-green foliage and in autumn by the size of its
=Bark.=--Bark of trunk and branches ash-gray, but darker than that of
the white oak, separating on old trees into rather firm, longitudinal
ridges; bark of branches sometimes developed into conspicuous corky,
wing-like layers; season's shoots yellowish-brown, minutely hairy, with
numerous small, roundish, raised dots.
=Winter Buds and Leaves.=--Buds brown, 1/16 to 1/8 inch long, conical,
scattered along the shoots and clustered at the enlarged tips. Leaves
simple, alternate, 6-9 inches long, 3-4 inches broad, smooth and dark
green above, lighter and downy beneath; outline obovate to oblong,
varying from irregularly and deeply sinuate-lobed, especially near the
center, to nearly entire, base wedge-shaped; stalk short; stipules
=Inflorescence.=--May. Sterile catkins 3-5 inches long; calyx mostly
5-parted, yellowish-green; divisions linear-oblong, more or less
persistent; stamens 10; anthers yellow, glabrous: pistillate flowers
sessile or short-stemmed; scales reddish; stigma red.
=Fruit.=--Maturing the first season; extremely variable; sessile or
short-stemmed: cup top-shaped to hemispherical, 3/4-2 inches in
diameter, with thick, close, pointed scales, the upper row often
terminating in a profuse or sparing hairy or leafy fringe: acorn ovoid,
often very large, sometimes sunk deeply and occasionally entirely in the
=Horticultural Value.=--Hardy in New England; in general appearance
resembling the swamp white oak, but better adapted to upland; grows
rather slowly in any good, well-drained soil; difficult to transplant;
seldom disfigured by insects or disease; occasionally grown in
nurseries. Propagated from seed. A narrower-leafed form with small
acorns (var. olivaeformis) is occasionally offered.
1. Winter buds.
2. Flowering branch.
3. Sterile flower, back view.
4. Sterile flower, front view.
5. Fertile flowers.
6. Fruiting branch.
=Quercus bicolor, Willd.=
Quercus platanoides, Sudw.
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