Featured Plant
Bur Oak, Quercus macrocarpa
In early October 2012, the UMD Arboretum planted three bur oak
trees to take the place of the Chapel Oak, our iconic white oak tree that died
and was removed in the summer of 2012. The bur oak, or Quercus macrocarpa,
is native to North America from the Appalachians to the Great Plains, south to
Texas, and east to the coast. It is very drought tolerant, and common in dry
uplands, sandy plains, and prairie grasslands. It has also displayed excellent
tolerance to urban pollution and was named the 2001 Urban Tree of the Year by
City Trees, the online magazine of the Society of Municipal Arborists. Bur
oaks are often used for shade trees, and are very slow-growing and long-lived.
They can eventually reach 100 feet in height with a long, clear bole and
wide-spreading form. They typically grow in the open, away from the forest
canopy, and are more common in the Midwest than in the east, because the forests
are less dense and there is less competition for sunlight.
Our new bur oaks are 5 inch caliper trees, moved with 90 inch
root balls, and were raised by nurseryman Joe Kraut at Pope Farm, the Maryland
National-Capital Park and Planning Commission’s tree nursery in Derwood,
Maryland. A member of the white oak group, the bur oak has alternate, simple
leaves, 6 to 12 inches long, that are roughly obovate in shape, with many
rounded lobes. The leaves are dark green above and lighter green and slightly
fuzzy underneath. The thick bark is ashy gray to brown in color and scaly with
vertical ridges. The extreme thickness of the bark enables bur oaks to survive
forest fires. On this monoecious tree, the male flowers are yellow-green and
borne on catkins, and the female flowers are green tinged with red, and appear
as short spikes. The twigs are stout and yellow-brown, often with corky ridges.
Next
Bur Oak images are courtesy
of Bob Callebert via flckr