Tree of the Week: Winged Sumac (Rhus copallina)

In mid-November we have an impressive show of autumnal color in the arboretum. Take a moment of your day to be dazzled by the brilliant hues. Some trees appear to be a single solid color of yellow or red, while other trees have a rich display of diverse colors. The motley tree pictured above is a winged sumac (Rhus copallina). It has a known history of stunning fall foliage, which you can read about here.

Tree of the Week: Winged Sumac (Rhus copallina)

Our tree of the week is a winged sumac (Rhus copallina), approximately 7 years of age, pictured center. This individual can be found along the concrete corridor that runs between Mickle Hall and the Student Union Building. You can see it in its autumnal splendor and read about its history on a previous blog post, here. This week we take a look at its flower clusters.

Winged sumac flower clusters are large and cream-colored with a tinge of green. Each cluster appears at the tip of a branch, surrounded by long, dark-green, compound leaves.

Despite their size, these flower clusters aren't particularly eye-catching, especially in comparison with the fall foliage of this species.

Each cluster is formed from innumerable tiny flowers. Unfortunately, these flowers appear to be fragrance-free. Low on visibility, low on odor, so how do the pollinators find them?

A small branch was cut for inspection, and leaf-removal was necessary for flower-inspection. Note the alternate arrangement of shorn leafstalks. 

This particular cluster measures 4½ inches long and 4 inches wide. It has an asymmetrical shape, perhaps because of its low placement on the tree—it developed upwards, towards the sun, rather than symmetrically.

Tree of the Week: Smooth Sumac (Rhus glabra)

You are hereby cordially invited to an informal, but important, ceremony: the induction of two volunteers to the arboretum catalogue. Join us, won't you?

These smooth sumacs (Rhus glabra) are growing near the long-established clump of sumac on the slope near Mickle Hall. Based on their vigorous growth and the locations of the young trees, we presume that they are shoots from the root system of the established plants. During the past two months, several sumac shoots have popped up in this area. The stunning fall foliage of this species makes it a desirable plant, so these specimens have been encouraged. Out of the half-dozen independent volunteers, the two individuals pictured below were selected primarily for their location: they are far enough away from the other trees to prevent over-crowding.

This hill slopes down from Mickle Hall. Hunter's Tree (red maple) and memorial bench are pictured center. The modest thicket of smooth sumacs is pictured behind and to the left of the bench. One smooth sumac volunteer is pictured on the far left of the frame, and the other volunteer is pictured on the far right. In a couple of years, this spot in the arboretum should give us an impressive show of red fall foliage.

This grouping of smooth sumacs was discussed last fall on the blog. Check out the post here.

There are more than 10 smooth sumac shoots in this clump. Most of the shoots are spindly and leaning, perhaps due to over-crowding and competition.

This volunteer was staked two months ago. It has survived the mowers, trimmers and dry summer weather.

The compound leaves are numerous.

The central trunk of this small, new tree is already more than a foot tall.

Our second volunteer is about a month old. It was staked two weeks ago. In years to come, we expect this little tree to help shade the sidewalk that runs down from Mickle Hall.

The little tree measures about a foot tall.

Tree of the Week: Winged Sumac (Rhus copallina)

Our tree of the week is the winged sumac (Rhus copallina). This small tree is doing more than its fair-share in the fall foliage game, and it's almost impossible to miss if you're walking between Mickle Hall and the Student Union Building. The young tree has an array of red, orange and green leaves, the red hues being amplified by the remaining green leaves.

Rhus copallina has been represented in the arboretum since 1995. In the fall of 1994, Ed Leuck collected two plants in town, along south Line Avenue, and he planted them in the ground the following autumn. One plant grew marvelously for many years. You can see pictures of it here. But this past spring, during a rain storm, the medium-sized tree unexpectedly fell over. Luckily, a clone of it remains. The small tree near the sidewalk popped up from the roots of the original tree approximately five years ago. Today it's providing marvelous color to the arboretum landscape and in years to come it will be providing much needed shade during the summer months.

This small, very colorful tree, is the arboretum's only winged sumac (Rhus copallina). It initially grew from the roots of an older tree which has since died; this specimen is approximately 5 years old. In years to come, it will provide much needed shade for this east-west walkway. The Mickle Hall auditorium is the brick structure pictured in the background, and you can see the campus greenhouse on top of the roof.

Winged sumacs have large leaves that turn beautiful colors in the fall. So much color!

There are still a few green leaves on the tree, and quite a few leaves are in the process of turning. The tree might be more stunning in this stage, while the red and green complementary colors are side-by-side, rather than when the tree has lost all of its greenness.

Winged sumac leaves are pinnately compound. The leaf on the left is missing a leaflet: back in the spring it surely had 11. The leaf on the right has 13 leaflets.

Underneath, the leaves are light green, considerably less stunning.

The winged sumac gets its name from the midrib, which is lined with protruding flat 'wings'.

For comparison, we have (partial) leaves from two different Rhus species. Rhus glabra is the mostly red leaf at the top of the photograph, and Rhus copallina is the multi-colored leaf at the bottom. 

Zooming in on the two different leaves, we see that the leaf stalk of R. glabra is thin and round. The R. copallina leaf stalk is flat and noticeably wider. This photo also shows that the leaflets differ: the leaf margins of R. glabra are toothed, while the leaf margins of R. copallina are smooth. 

The branch bark is a silvery gray.

You can see old pictures of the arboretum's recently deceased winged sumac here.

For more information about this species consult the following:
United States Department of Agriculture
Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter)
University of Florida (IFAS Extension)

Tree of the Week: Smooth Sumac (Rhus glabra)

We first noted the fall foliage of the smooth sumac (Rhus glabra) back in September, in an 'Autumn Update'. The transformation is now complete: all the leaves have turned red, of varying shades. 

The smooth sumac entered the arboretum collection in October 1996 when Ed Leuck collected several specimens from the wilds of Caddo Parish. These were nurtured in pots until 1998 when they were planted in the ground on one of the arboretum's many clay slopes. By the year 2000, the sumacs in this initial planting had sent out their roots and established a second patch. The smooth sumacs you'll see today in the arboretum (and in the picture below) are from the second patch; the original plantings were later removed.

Smooth sumacs tend to develop as bushes rather than trees. In this grouping, which has been growing since 2000, there is one small tree and approximately 10 younger, smaller shoots, forming a thicket.

The trunk of the small tree can be identified in this photo. It appears to be leaning to the left.

Another view shows that the tree is leaning down-slope and seems to be partially propped-up by a rock.

In the fall, smooth sumac leaves are stunning shades of red.

The compound leaves are very long. This one measures more than 18 inches.

The underside is a pale pink.

The long-pointed red leaflets have toothed margins. In this photo we can see that the petioles are red, too.

This leaflet measures to 4 inches.

This is the trunk of the small tree, approximately 17 years of age. The bark is dark gray and lightly textured.

You can see more pictures of the arboretum's smooth sumacs here.

For more information about this species consult the following:
Texas Native Plants Database (Texas A&M University)
United States Department of Agriculture
NC State University 

Rhus copallina

 

Young foliage

Mature foliage

Rhus glabra

 

Toxicodendron radicans ssp. radicans

Synonymous with: Rhus radicans