Tree of the Week: Southern Sugar Maple (Acer barbatum)

 

Our tree of the week is a particular southern sugar maple (Acer barbatum).

The southern sugar maple is pictured center. It is approximately 30 years old. In 1995, Mr. Jack Price donated this maple, from "Alabama stock", to the arboretum collection. At the time, it was four feet tall.

Looking from across the pond, we see sugar maple leaves blanketing the slope that leads up to the Student Union Building.

A view from the long white wooden bridge, photographed December 5, 2021

Our tree of the week is not fully responsible for all of this pleasing coloration. Several species of maple are planted here: chalk, box-elder, red, and sugar. However, the southern sugar maple is the top contributor this week. All of these leaves have dropped since Wednesday, when the lawn mower went through the arboretum mulching leaves.

 

Examining the leaf litter we primarily see southern sugar maple leaves.

Acer barbatum leaf litter, photographed December 5, 2021

 

 

Tree of the Week: Southern Sugar Maple (Acer barbatum)

There are three distinct maple enclaves in the arboretum. One such location is pictured above. This spot near the Student Union Building has great comparative value for our maples: you can easily examine 1) boxelder, 2) chalk, 3) red, and 4) southern sugar specimens. Last week we examined the boxelder. This week we are turning to the southern sugar.

There are four southern sugar maples (Acer barbatum) in the arboretum collection. You can see additional pictures of these individuals here and here.

Our tree of the week is pictured center. It was previously featured to highlight its shadiness. You can see evidence of that attribute and read about its history here. This week we are back, taking leaf and samara measurements. Hold on, little maple; this will only hurt a bit.

Southern sugar maple leaves are simple with a palmate shape. Leaf base measures 3 inches. Overall width measures closer to 4 inches.

Leaves are approximately 3 inches in length.

Petioles are long. This one measures more than 3 inches.

In mid-July, well-developed orange-colored fruits standout against the dark green foliage.

Specifically, the wings of the samaras make the fruits conspicuous. Each orange wing is attached to an enclosed seed. The bulbous seed coating is the same green color as the dorsal side of the leaf.

Underneath, leaves are pale green, verging on white. Note that the samaras are clustered together.

Each samara consists of one wing and one enclosed seed. Two seeds are fused together, making a pair.

Each samara is approximately an inch in length.

Each pair measures approximately 1½ inches across.

Samaras can help us differentiate among the maple species. Boxelder samaras are pictured on the left: these fruits appear in long, dangling chains, and in the middle of July, they are inconspicuously light green.

Winter Fall Foliage: Southern Sugar Maple

The yellow leaves belong to a southern sugar maple (Acer barbatum). This tree was purchased from Woodlanders Nursery (Aiken, SC). It was planted in 1999, making the tree approximately 20 years old.

This fall foliage was photographed the day after the winter solstice.

The green leaves pictured in the bottom right belong to an American holly (Ilex opaca), which is an evergreen. The American holly is a volunteer, first noted in 2002. These two trees are competing for sunlight: the southern sugar maple remains the taller of the two trees, but not by much.

Tree of the Week: Southern Sugar Maple (Acer barbatum)

Our shade tree of the week is the southern sugar maple (Acer barbatum), widely reported to be an "excellent" or "wonderful" shade tree. This is a medium sized tree; it grows large enough to shade a big area, but not so big that it becomes a hazard. And it delivers another service: after laboring all summer to provide us with relief from the sun, we are rewarded in the fall with showy, yellow foliage.

Southern sugar maples do well in the Centenary Arboretum. There are four individuals in the collection and they are all healthy, mature specimens. The pictures below are of an individual tree planted near the Student Union Building. The specimen was collected in 1994, from Walter Jacobs Nature Park, and subsequently planted in January 1996, making this tree well over 20 years old.

This individual southern sugar maple (Acer barbatum) is planted along the sidewalk going towards the Student Union Building. The grass under the tree is nicely shaded while the concrete sidewalk is brightly lit-up by the noon-day sun. The photo above shows the shadow of the tree creeping onto the sidewalk, and hopefully in the next several years the sidewalk will receive more coverage.

Although the concrete sidewalk is currently exposed to full noon-day sun, the gravel path is shaded by the Acer barbatum.

We have full-shade under the tree and full-sun on the other side.

Leaves of Acer barbatum are characteristically lobed.

Leaves are dark green in the summer, and we can expect them to turn yellow in the fall.

Looking up, Acer barbatum blocks the sun.

Trunk of mature tree, more than two decades old.

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

For more information about this species consult the following:
Stephen F. Austin State University 
NC State University
US Forest Service 

Acer barbatum