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Burr oak

Bur oak
Quercus macrocarpa USDA.jpg
Bur oak leaves and acorn
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Fagaceae
Genus: Quercus
Section: Quercus
Species: Q. macrocarpa
Binomial name
Quercus macrocarpa
Michx. 1801 not Endl. 1848
Quercus macrocarpa range map 1.png
Natural range
Synonyms

Quercus macrocarpa, the bur oak, sometimes spelled burr oak, is a species of oak in the white oak section Quercus sect. Quercus, native to North America in the eastern and central United States and eastern and central Canada. This plant is also called mossycup oak and mossycup white oak.

Quercus macrocarpa is widespread in the Atlantic coastal plain from New Brunswick to North Carolina, west as far as Alberta, eastern Montana, Wyoming, and northeastern New Mexico. The vast majority of the populations are found in the eastern Great Plains, the Mississippi/Missouri/Ohio Valley, and the Great Lakes region.

Quercus macrocarpa is a large deciduous tree growing up to 100 ft (30 m), rarely 130 ft (40 m), in height, and is one of the most massive oaks with a trunk diameter of up to 10 ft (3 m); reports of taller trees occur, but have not been verified. It is one of the slowest-growing oaks, with a growth rate of 1 ft (30 cm) per year when young. A 20-year-old tree will be about 20 ft (6 m) tall if grown in full sun. Naturally occurring saplings in forests will typically be older. It commonly lives to be 200 to 300 years old, and may live up to 400 years. The bark is a medium gray and somewhat rugged.

The leaves are 3–6 in (7–15 cm) long and 2–5 in (5–13 cm) broad, variable in shape, with a lobed margin. Most often, the basal 60% is narrower and deeply lobed, while the apical 40% is wider and has shallow lobes or large teeth. The flowers are greenish-yellow catkins, produced in the spring. The acorns are very large, 0.75–2 in (2–5 cm) long and 0.75-1.5 in (2–4 cm) broad, having a large cup that wraps much of the way around the nut, with large overlapping scales and often a fringe at the edge of the cup.


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Wikipedia

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