Tree Removal: Box Elder Maple (Acer negundo)

 

This week we say goodbye to a box elder maple (Acer negundo). We do not know the age of this tree. It was a volunteer, and when it entered the catalogue, an approximate age was not given.

 

This tree has been tagged for removal since spring 2020, after it suffered significant storm damage. You can read about it and see pictures of the storm damage here. In the above photo, we see a thick, straight trunk and dense foliage up top. It's clearly alive.

Up close and personal, it's truly awful.

Here we see fungal growth, mold, missing bark, and insect damage.

This is extensive, running across half the circumference.

At about four feet up the trunk, the tree had a circumference of 30 inches.

The first step in removal is to take off lower branches.

Then the crown and all the other branches were removed, leaving only the trunk.

The trunk was taken down in one piece.

There was an entire ant civilization living in the caverns of this tree, fifteen feet off the ground. Luckily they could only bite and not sting with venom.

After stump removal, there's not much evidence of this tree's relatively short life. Its memory will be preserved on this blog and our records.

Spring Storm Damage

What a mess! We have had a stormy spring in northwest Louisiana. This week alone brought two severe thunderstorms. High winds knocked old limbs loose, littering the ground with debris. For the most part, the arboretum has suffered little damage. The only significant damage is pictured above: an older, sickly tree lost its crown.

The top of a box-elder maple (Acer negundo) rests partially on the ground and partially on the surrounding vegetation. 

The box-elder maple has been in poor health for years. Squirrels repeatedly stripped bark from its limbs and trunk, making it impossible for the tree to heal itself. This has resulted in a weakening of the structure, and ants have colonized the tree.

Even though a third of the tree broke off from the top, this maple is by no means dead. If allowed to grow unhindered, this tree would live for many years to come, with new shoots steadily appearing along the lower portion of the trunk. However, for aesthetic reasons, this individual is tagged for removal.

Tree of the Week: Boxelder Maple (Acer negundo)

The boxelder maple (Acer negundo) is a fast-growing, drought-tolerant shade tree that naturally occurs in river bottoms with the likes of willows and cottonwoods but will grow under a wide variety of conditions. Our tree of the week, pictured center, is a 25-year-old boxelder. In 1994, it unexpectedly appeared growing in a pot in the campus greenhouse, located on the second floor of Mickle Hall. Two years later it was planted in the ground of the arboretum, only to be dug up 6 months later to avoid a construction crew. In March 1997, the boxelder was replanted in its current location.

Our boxelder maple helps shade the gravel path that runs from the Student Union Building to the Fitness Center.

Backing up, we can appreciate a slight westward bent. The boxelder leans westward because to the east a southern sugar maple out-competes it for sunlight.

Unlike all other maples, boxelders have compound leaves. These pinnately compound leaves typically have 3 or 5 leaflets. Leafstalks are long, and they appear opposite from one another along the branchlet. In the photo above, we have a branchlet with 11 leaves and 33 leaflets.

This particular leaf has 5 leaflets. Leafstalk and leaflets together measure 10 inches in length.

Leaflets vary in size and shape, even on the same leaf. Ovate or elliptic leaflets with coarsely toothed margins are common. It's also common to see lobed leaflets. Leaves of young boxelders are often mistaken for poison ivy (Toxicodendron radicans).

In this first week of July, the pale-green, immature fruits hang in long clusters from boxelder twigs. The fruits are numerous, but not showy.

This cluster of fruits measures more than 5½ inches in length. Our tree of the week is laden with these inconspicuous drooping ornaments.

Like the other maples, boxelders produce samaras, which are winged seeds. Each seed is attached to one wing for wind dispersal. The samaras appear in pairs attached to a stalk, altogether measuring more than 2 inches in length.

Of course, nature is full of exceptions. Here we have 3 samaras fused together.

Our 25-year-old boxelder has rough, light-gray bark with shallow furrows.

Surface roots are noticeable along the gravel path.

Surface roots can become tripping hazards and the roots themselves commonly suffer damage from trimmers and lawn mowers.

Note the splotches of orange bark on this surface root.

You can find more pictures of the arboretum's boxelder maples here.

For more information about this species consult the following online sources:
United States Department of Agriculture
U.S. Forest Service
Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter)
Virginia Tech Dendrology 

Acer negundo

 

The bark of branches and young trunks characteristically retain their smooth, green appearance.