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Monday, June 26, 2017

Trees of Washington D.C. - the Capitol Region by Matthew Hannum

Trees of Washington D.C. - the Capitol Region


Each year, great numbers of tourists visit The Mall in Washington D.C.
to see the various monuments and museums that line the streets of this
impressive city. D.C. is steeped in history and is a great place to
visit even if you are there mostly for to see examples of nature, which
is surprising for a city. Old trees live among equally old buildings and
monuments, silent witnesses to years of history that have passed under
their limbs and leaves.

This article will focus on the area around the Capitol Building, the
grounds of which house a good number of old and massive trees, many of
them native to the United States.

- Northern Red Oak: A great number of these line the roads and open
areas between Union Station (how I get too and from D.C. from points
northward) to the Capitol Building. Most of the red oaks here are not
terribly old, though they are still older than the average tree on a
suburban lot. An increasing variety of other oak species is being
planted in the area, which is good since it should help get away from
the near mono-culture of northern red oak.
capitol_willow_oak.jpg (193430 bytes)
Capitol Willow Oak - 20'4" CBH X 105.2' HGT X 90' AVG spread

- Willow Oak: The first truly huge, native tree one will come across
when walking from Union Station to the Capitol. There, on the northward
side of the Capitol, stands a monstrous willow oak. While the tree's
height and spread are respectable, but not tremendous (since it is
open-grown), it's girth is rather staggering. I'm quite sure it is over
5-feet in diameter, with a big root structure holding it in place. Truly
an impressive tree that seems to stand like a pillar holding up the

- Black Walnut: A modest-size black walnut grows opposite the path from
the huge willow oak. It is not very large or impressive in size, but it
is worthy of note.

capitol_pecan.jpg (250412 bytes)
Capitol Pecan

- Pecan: A large pecan tree stands amid some other Northern Red Oaks if
one heads up the path, away from the Capitol, from the huge Willow Oak.
This pecan tree has a distinct southward lean to it, but is in good
health. Like most members of the pecan and hickory family, it has more
height than spread and has most of its limbs higher up in the canopy.
I'd say it is over 3-feet in diameter, maybe more, which may not be
terribly impressive, but it is a nice tree that I'd recommend seeing
while in the area. In 2006, it produces a heavy crop of pecans, so the
squirrels at least appreciated it.

- Buckeyes (Ohio and Yellow): A good number of these trees live on the
Capitol grounds, but some of them are not in the best of condition. Many
of the Ohio buckeyes are in decline, and some of the yellow buckeyes
have seen better days as well - one of the larger ones had a big
mushroom growing from an old wound in the fall of 2006, which is not a
good sign. Fans of buckeyes will be impressed by these trees, but I do
get the impression that buckeyes are not the longest lived of trees
based upon what I've seen here. They are also very messy - I'd hate to
be hit on the head by the melon-sized fruits dropped by the yellow
buckeyes, each of which contains about 3 big, hard, glossy black nuts.

- White Oak: At least one of these trees stands on the southern areas of
the Capitol grounds. It has the distinctive flaky bark of older white
oaks, and though it is a decent size, they don't grow as fast as other
oak trees. Still, they live a long time, so these trees will be here a
while (unlike the buckeyes, I suspect).

- Sugar Maple: A gnarly sugar maple lives on the southward side of the
Capitol, closer to the building itself. Like all of the hardwoods in the
area, it has a trunk that I think is over 3-feet in diameter; it also
probably has very impressive colors in the fall, though it was early in
the season when I visited it this year.

- Swamp White Oak: A large member of this species grows near the sugar
maple. Again, like most members of the white oak family in the area, it
is not as large as the red oaks, but it is still an impressive tree with
nicely grooved bark.

capitol_sequoial.jpg (260723 bytes)
Capitol Giant Sequoia

- Giant Sequoia: Yes, oddly enough, one member of this species grows on
the southward side of the Capitol. It looks more like an overgrown shrub
with an unusually large trunk - I'd never have guessed it was a Giant
Sequoia if it were not for the sign saying so! I doubt it will ever
reach huge sizes, but it will probably live a long time as a rather
stunted shrub-tree.

- Lindens (Various): A good number of lindens (big-leaf, little leaf,
etc.) grow on the Capitol grounds, but none of them caught my eye as
particularly large or old.

- Osage Orange: Two of these strange trees grow on the southward side of
the Capitol. Neither one is impressive as a shade tree, though I get the
impression that Osage Orange is more of a small tree anyway. At the time
(early October of 2006), they were dropping their strange, green,
brain-like fruit all over the ground. These fruit are truly weird
looking, and as I've read in other places, nothing seemed interested in
eating them.

- Ash (White and maybe green): At least two ash trees live around the
Capitol, but both are in decline. When grown out in the open, ash trees
seem to have a bad habit of putting out large, massive, lower limbs at
wide angles to the main trunk. These limbs then snap off in storms. Both
of the ash trees I saw showed obvious signs of such problems, and I
think they were both wired and cabled to hold them together.
Forest-grown ash trees grow straight up and don't have this problem.

- Tulip Tree: Only one tulip tree graced the Capitol grounds, and it was
a broken-down ruin. While still covered with leaves, the main trunk
shattered many years ago, leaving a stubby tree behind.

- Elm Hybrids: Several "hybrid elms" of good size live around the
Capitol. I don't really know what they are hybrids of, and I guess that
they were labeled hybrids since they were not purely American elm and
they have dodged Dutch Elm Disease.

capitol_burr.jpg (196401 bytes)
Capitol Burr Oak

- Bur Oak: I read about the existence of this tree online - if you leave
the immediate area around the Capitol and go past the Reflecting Pool,
you will find this tree on the other side of the Pool on the southward
side. It is not labeled, unfortunately, but it is a huge tree with a
massive, stout trunk and a crown of big, heavy, strong limbs. It is not
as large as the huge willow oak and doesn't have the large, exposed root
structure, but it is almost as massive and probably one of the largest
trees in the area, at least by volume and mass.

The Bur oak at the time was dropping it's trademark HUGE acorns on the
ground. This was the first time I've ever seen the acorns of this
magnificent species of tree. They are as large as golf balls with big,
shaggy caps. The ground below the tree was covered with them, though I
oddly saw few squirrels going after them. This may have been because of
all the people walking to and fro under the tree, or perhaps the very
large acorns pose a problem for the squirrels to transport. Either way,
it was amusing watching the look on peoples' faces as they had to slow
down and watch their step below the big tree. Kids expressed surprise
and often ran to pick up one of the huge acorns, while adults often
looked confused as to how they could be walking among such strangely
large acorns. I collected a few of the big acorns myself and planted a
few them amid other oak trees out in the woods - maybe I'll have some
bur oaks eventually. It is too bad this tree is not labeled since I bet
many people would love to know what it is after seeing the huge acorns.

- Summary: It was interesting to walk the grounds around the Capitol and
see the trees there since they are a good representation of the larger
hardwood trees that live in eastern North America. There are some areas
lacking - they could really use more members of the hickory family and I
think they've overdone the planting of northern red oaks - but the
collection of trees here is quite impressive and well worth visiting. I
am sure that I did not find all the specific trees in the area, and
other walks around The Mall and D.C. in general will reveal more trees
of various species.

It was also interesting to note that there must be very distinct climate
conditions influencing the trees in the area. None of the trees were
stunningly tall, and many seemed to take on a more squat and wide growth
pattern. Part of this is because they are open-grown and not competing
with each other in a forest, but I also wonder if D.C. sees serious
storms or winds that may limit the growth of normally very upright
species. The only tulip tree was "topped" by nature years ago, the tall
pecan tree has a distinct lean to it, the giant sequoia is not so giant,
the ash trees show signs of serious wind damage to their heavy limbs,
etc. While the trees do receive good care and have plenty of water and
sun with which to grow, they may face down some serious storms now and
then in D.C.

I hope that you enjoy this article and get a chance to visit D.C. for
its trees at some point!

Mathew Hannum
"Yet it is not our part to master all the tides of the world, but to do what
is in us for the succour of those years wherein we are set, uprooting the
evil in the fields that we know so that those who live after may have clean
earth to till. What weather they shall have is not ours to rule."

- Gandalf the Grey, The Return of the King