GARDEN TALK
Osage Orange: The Original
Barbed Wire of the U.S.
By Matt Lahm,
Assistant Curator of Conservation Education
Around this time every year, one
tree becomes particularly noticeable
because of the fruit it produces.
Maybe you’ve seen it too — a tree
with fruits that are inedible but
distinctly large and fleshy. The fruits
are nearly the size of a grapefruit
or large orange, but with a warty
green surface sparsely covered with
long, coarse hairs.
The tree is the Osage orange
tree, Maclura pomifera, named
after the Osage native Americans
who lived in the tree’s original
home range, namely the Red River
valley of southern Oklahoma and
northern Texas. The tree is known
by several other colorful common
names based on locality like hedge
apple, mock orange, horse apple
and bow wood.
Osage orange trees are easily
recognized by their fruit and their
glossy, lance-shaped leaves. They
can be either male or female but
only the females bear fruit. The
wood is considered one of the most
durable woods in North America. It
was once in demand to make hubs
and wheel rims for horse drawn
wagons, and even mine-support
timbers and posts because of its
extreme resistance to decay.
Probably the most important
use of Osage orange trees in U.S.
history was its use as fencing for
livestock. When the tree is a young
sapling or when it is damaged as
it gets older, it produces branches
with one-inch thorns at the base
of each leaf — an adaptation to
protect itself from large herbivores.
These growth habits caused it to
be considered the
best fencing material
available to settlers.
Many thousands of
miles of “hedge”
were constructed by
planting young Osage orange trees
closely together in a line. The sap-
lings were aggressively pruned to
promote bushy and thorny growth.
"Horse high, bull strong and hog
tight” were the criteria for a good
hedge made with Osage orange.
Tall enough that a horse would not
jump it, stout enough that a bull
would not push through it and wo-
ven so tightly that even a hog could
not find its way through!
Here at the Zoo, we use the
Osage orange wood for a number
of things. You may have noticed
the large Osage log along the
discovery trail in Gorilla Forest.
The climbing structure in the
Islands Dayroom that orang-
utan Amber climbs on is also
made of Osage wood. There
are Osage logs in the jaguar
exhibit and in the porcupine
exhibit. “The wood is highly
coveted by the keeper
staff,” said Mam-
mal Curator
Jane Anne
Franklin. The
Louisville
Zoo hor-
ticulture
staff plants
Osage or-
ange trees
near the
Zoo borders
16 • Louisville Zoo Trunkline • Winter 2017
Thorns from Osage orange limb.
to harvest for future exhibit use due
to its remarkable durability.
On your next visit to the Zoo,
take a look around near Zoovision
or the rhino exhibit and
enjoy viewing this dis-
tinctive tree in person.