Coral Bean (Erythrina herbacea)

There are two coral bean (Erythrina herbacea) plantings in the arboretum. One is located on the north side of the Fitness Center, unfortunately placed in the shade of a hickory and an ever-spreading Chickasaw plum (Prunus angustifolia). The other coral bean has a more advantageous spot at the southwest corner of Mickle Hall. The latter plant has a flower stalk this week.

 

The flower stalk demands attention as it protrudes from the greenery of the coral bean, but the fresh spring-time growth of the nearby French mulberry and toothache tree conceal the bright red flower. 

 

Keep an eye on this flower stalk if you have an interest in collecting the pretty 'beans' that are expected to develop here. The arboretum curator has had zero luck in germinating the seeds in the past, so please feel free to collect them when they are ready. Good luck!

 

Pyramid Magnolia Germination Project Update

Back in February, we planted 15 pyramid magnolia seeds that were provided by the Atlanta Botanical Garden. Our first seedling revealed itself this past Sunday. Wahoo! We have a picture of our first and timeliest seedling: 

 

Pyramid magnolia (Magnolia pyramidata)

 

 

Loblolly Pine (Pinus taeda)

A young pine tree in the arboretum is now in need of a sign. Due to uncertainty about its species, we have delayed creating an official arboretum placard. To see the post from March 2023, when this specimen entered the arboretum collection, click here. 

Upon collection from the wild in a wooded area north of Shreveport, the tree was so young and small that it lacked obvious species-defining features. It just looked like "native pine." Rather than risking misidentification, which can be a more-or-less permanent issue, we left its classification an open question and waited...for years.

In spring 2026, our young "native pine" is looking more grown-up! 

This fine specimen grows on the grassy slope north of Cline Hall, an area that is open and sunny, but is steadily planted with young trees.

We can confidently identify this specimen using photos of its needles and flowers, its male cones. It's a loblolly (Pinus taeda). No surprises here! In our region, this is a default and commonplace pine, especially dominant in forestry. Its lumber is often sold as SYP (Southern Yellow Pine) and its binomial name Pinus taeda is a Latin-Greek mashup that could be translated as 'Pine-pine' or 'Resinous Resin-tree.' This name doubles-down, to an unusual degree, on the piney-ness of this tree.

This tree is developing a proper and upright growth pattern due to its generous allotment of sunlight and favorable position. Young trees in the wild will be spindly due to the "battle of the understory" that most of them undergo.

Here's the source of that delightful yellow dust covering your car, your outdoor furniture, your pets, etc. Achoooooo!

The identifying features that the juvenile tree lacked: fully-developed needles and reproductive structures. This is the first year that we have seen flowers on the tree, and not many are present. 

 

The fully-developed needle clusters come in trios and are around 6-7 inches long. A shortleaf pine would have needles half that length and usually come in twos. Longleaf pine needles come in threes, but would generally start at 8" in length.

 

The pollen cones are yellow, banana-shaped and approximately an inch in length. Longleaf pollen cones are a startling blue-purple or an orange-red. Shortleaf cones are similar in color and shape to loblolly, but tend to be only half-an-inch or a little larger.

 

There are several on-site native mature loblolly pines in the arboretum and on the campus as a whole, so we might argue that the arboretum doesn't need 'just one more loblolly....' However, the campus loses at least one mature loblolly each year, so it's important to continually replace those old pines. And, it's super neat to see the different stages of a tree's development because as they age, loblolly pines lose those lower branches and we only see that beautiful brown, seemingly perfectly round trunk. So, we are happy to have this young loblolly on that grassy slope in front of Cline.

 

For further online reading, please consult the following websites: 

NC State Extension page on Loblolly Pine 

Article on Loblolly from "The Tree and Its Environment" (1990) 

Ladybird Johnson Wildflower Center page on Loblolly 

Sweetgum (Liquidambar styraciflua)

Currently we have only one sweetgum (Liquidambar styraciflua) in the arboretum collection, and it is still very young. The sole specimen originated from a trip to East Texas in 2022. That fall, we collected a pocketful of gumballs from a wooded area in Cherokee County, Texas, close to the small town of Maydelle. Those gumballs were brought back to Shreveport and shaken into a pot of dirt where the seeds overwintered. Three seedlings came up the following spring. On March 10, 2025, we planted one of the three on campus, outside of the arboretum proper: it's on the Fitness Center lawn, between the Fitness Center ramp and the Cline Hall parking lot. Today, we have a hearty young specimen that nicely displays the characteristics of the species. The following photos show the tree after three years of growth. 

An old sign for a new tree. We like to recycle and re-use our materials in the arboretum.

 

The 3-year-old tree is 21 inches tall with a straight and sturdy trunk.

This one is planted *near* the parking lot but not next to the parking lot. Looking into the future, we see a towering tree with an excessive number of fruits that are falling on the *grass* rather than the cars and pavement. Nobody likes a "trash tree"....

 

While this tree isn't quickly growing tall, it is forming a thick trunk. Have the interesting bark formations drawn your attention?

Young sweetgum stems have irregular 'wings' or corky ridges, like our winged elm (Ulmus alata). The contrast between the green branches and the grey plates is distinctive.

This little tree is ready for spring. 

 

Fresh green leaves unfurl in a bold salute to Spring.

 

We see the characteristic sweetgum leaves in miniature.

Now that it's well-established, will it show rapid and vigorous growth this year?

March Blooms in the Arboretum

Spring doesn't officially begin until the vernal equinox, which is still about two weeks away. But the weather, the animals, and the plants have decided that, for us in Shreveport, the season has arrived in advance of its astronomical formalities. 

Glorious flowering from our Mexican plums (Prunus mexicana) this week.

 

At this time, the flowers have a powerful, distinct, and not altogether pleasant aroma.  Nature's a funny thing.

Here we have a post from March 2019 featuring the same delightful Mexican plum blossoms. And a post from this time last year showing our efforts to transplant some new Mexican plums. Leafing-out season will tell us if that was successful.

Elsewhere in the arboretum, you can find flowers of the paw paw (Asimina triloba). These are less-showy. You will need to go looking for these along the drainage channel that runs north to south through the arboretum.

The juxtaposition of these deep crimson-purple bells alongside the green bells is unforgettable.

We attempted some cross-pollination. Good luck, little tree.

See our post from last summer on planting new paw paw and a similar springtime post from 2022 that features paw paw flowers.

Germination Project: Pyramid Magnolia

The Centenary College Arboretum is participating in a pyramid magnolia germination project organized by an international team, the Global Conservation Consortium for Magnolia, headed by the Atlanta Botanical Garden. Your arboretum curator has taken on custody of 15 seeds collected from pyramid magnolias (Magnolia pyramidata) growing in east Texas. The seeds were initially collected in August by a group working out of the Lady Bird Johnson Wildflower Center. In September, we at the Centenary College arboretum agreed to join the germination effort. Our 15 seeds arrived at the campus post office on February 17th, and we potted them the following day. The Seed Propagation Protocol forwarded by the Consortium tells us that seeds from a 2025 germination project had a high germination rate and sprouted, on average, 53 days after sown. Consequently we can expect seedlings to pop up around April 12th. 

We received a total of 15 seeds, separated into three different bags. Each bag was marked with a number.  

 

In one bag, we received 6 seeds, pictured in the above photo, with an identifying number: SB-20250563. We also received two additional bags, one with 4 seeds and another with 5 seeds. 

Each seed has its own 3-inch pot to call home.

 

Seeds measure ¼ inch in length.

 

Our 15 pots are organized in three groups. We are hoping for 15 seedlings!

You can find more information about the project organizers by following these links:

The Global Conservation Consortium for Magnolia 

Atlanta Botanical Garden 

Black Oak (Quercus velutina) Removal

It's time to retire another specimen from the arboretum, again due to disease and being crowded out by the more successful. A 30-year-old black oak (Quercus velutina) was cut down this past weekend, making more room for its partner tree, a southern red oak (Quercus falcata). On the blog, we saw them first in a post from 2012, as photographed by Bonnie Bernard. Then in 2019, showing both trees healthy.

 

In our last photos before removal, we see the much thinner, leaning black oak trunk and the large, straight southern red oak trunk. Each tree has a sign near the base of the trunk, hopefully helping visitors understand that they are in fact looking at two separate trees―not a tree with two trunks. These two have served as a marvelous example of what competition can look like among trees.

The black oak was intentionally planted with care in 1996. Some time later, the southern red oak volunteered in the same spot and was allowed to grow. Over the years, the red oak has squeezed (strangled?) the black oak out of this location. Earlier this year the black oak finally gave up the fight―it dropped its foliage and the trunk quickly showed signs of deterioration.

On the trunk, just before its removal, we see obvious signs of decay, including bugs scurrying across the pitted, fungal bark. It could remain standing for years before falling in an ice storm or windy weather event. The major reason for removal is unsightliness, followed closely by health risks to the partner-tree. The southern red oak has grown into a very handsome tree.

With the black oak trunk on the ground, we see one long straight trunk with very few branches.

A small brush pile was made from the sparse branches. We broke up the trunk and removed it. Despite some rotting, especially around the bark, most of the trunk wood was solid and hard.

The fall landscape is altered with the removal of the black oak. Note: it's mid-December, and some of our maples are still changing colors; the chalk maples (Acer leucoderme) on the slope are turning yellow-orange and a red maple (Acer rubrum) in the background is a bright red-orange, even on such a cloudy day.

Ideally we want to remove this stump. It's like a dead tooth which provides a disease reservoir for the gums in which it sits. But this stump cannot be easily removed from the healthy trunk of the neighbor which has eclipsed and ultimately killed it.

We will leave the sign in place for a little while, to remind us of the spirited competition and also to remind us to check on the decaying process. Will the southern red oak trunk grow to completely encapsulate the decaying trunk, leaving no sign of the black oak's existence?