Education & Outreach

An academic arboretum has two purposes. In its fundamental and most basic role, such an institution serves as a repository for living specimens and the germplasm of plant species. If this goal has been accomplished, a secondary role can be achieved: showcasing these specimens to students and the public, with the intention of increasing knowledge about those trees, shrubs, and herbs. Because they exist in physical space and not as a description in a book or on a computer, the arboretum's cataloged specimens can be seen year-round and from 360 degrees. You can "zoom in" and look as close as you want. Can't find just the right photo of a tree? Go snap one yourself at the arboretum. If you like the organism enough, you may be able to collect some seed and start your own. Short of cutting the specimen down or doing permanent damage, every plant in the arboretum is part of an interactive experience; no screens involved.

In support of this ideal, today we'll show some photos of a recent arboretum tour that Centenary College's Visual Identity and Publications Manager Sherry Heflin was kind enough to photograph. Normally, photos of tours given at the arboretum are not available, since the curator cannot photograph herself while thinking, walking, and speaking. Perhaps the arboretum needs a very expensive autonomous drone with a nice lens for such occasions. Then again, Skynet drones might disrupt the ambience for a group that is supposed to be experiencing nature. 

 All photos below were taken by Sherry Heflin, on October 21, 2024.

The tour began in the oldest part of the arboretum, between Hamilton Hall and the Student Union Building. One of the four black metal arboretum signs marks the northern edge of the arboretum.

For a tour during the fall, fruits are a great topic. The arboretum has many different species of oaks growing in a small area, so it's easy to find acorns and compare them. These small acorns were collected under a water oak (Quercus nigra).

This big acorn was snipped from a Burr oak (Quercus macrocarpa).

Persimmons are ripe this time of year! Here, the arboretum curator holds an example of a perfectly ripe persimmon (Diospyros virginiana).

French mulberry fruits are also edible, but not recommended. These pretty purple fruits weren't as numerous in late October.

The arboretum curator displays the very small seeds of the redbud (Cercis canadensis).

In the arboretum, there are plenty of opportunities to play the game: 'Where's the tree? Where's the vine?'. Here, the arboretum curator points out bright red fruits hanging from a black cherry (Prunus serotina). The bright red fruits actually belong to a vine, Carolina moonseed (Cocculus carolinus).

Ouch! These spiny fruits were produced by the American chestnut hybrid, Dunstan (Castanea dentata).

The arboretum has numerous red buckeyes trees (Aesculus pavia). Here, a Centenary students opens a buckeye fruit, looking for the large seeds.

Buckeye seeds are shiny and look oily. What do you think they smell like?

Competition over resources wasn't the focus of this tour, but a few examples were pointed out. Here we have an interesting example. Two trees are shown here. Their trunks have grown together. The slender trunk, leaning toward the left, belongs to a black oak (Quercus velutina). It was intentionally planted. The big trunk, growing straight up, belongs to a southern red oak (Quercus falcata). The red oak volunteered a few years after the black oak was planted, and the red oak has out-competed the black oak for sunshine, water and nutrients.

Even what looks like a bare stick is worth talking about. At the beginning of the tour, the arboretum curator explains that these is the arboretum's original patch of Hercules-club (Aralia spinosa), planted in the old part of the arboretum, circa 1990. Only three spindly plants remain.

Later in the tour, the arboretum curator points out a thriving grouping of Hercules-club. Here, the curator stands among the Hercules-clubs, holding two trunks. These plants are younger, and yet they are significantly larger. Viewing these plants in person and walking through the landscape, we can easily start to formulate hypotheses.

There is always something to talk about in the arboretum. The landscape is always changing!

Southwest Corner of Mickle Hall

Architectural plans for the renovation of the Centenary College science building, Mickle Hall, include an addition to its west side. The building project necessitates the removal of a significant number of specimens from the arboretum catalogue. A small number of individuals can be transplanted; that work has already begun (see here). Unfortunately, most of the trees will perish in the name of progress, as they are too large and too old to relocate. In this post we will continue to document the appearance of the arboretum before the renovations change its layout. Below, we take a look at one of the groupings of plants.

Here we see the southwest corner of Mickle Hall. In early January 2022, a mature post oak (Quercus stellata), in declining health, was removed from this location. It stood to the right of the entrance. During the course of the proposed renovation, we will see the removal of the grouping of plants to the left of the entrance.

All of these plants will be removed. Within the leaf litter, there are several seedlings that could be collected and potted for future plantings within the arboretum, but all of the larger plants will be cut down and/or torn up with machinery.

In this photograph, we see the arboretum shed on the far left. It will also be removed, as Mickle Hall is expected to expand into this area.

The largest individual in this grouping is a toothache tree (Zanthoxylum clava-herculis). We have discussed this individual on previous blog posts, found here. It is very tall and over 15 years old. With the proposed addition to Mickle, it will die. However, looking on the 'sunny side of life', we must note that two seedlings were identified in the leaf litter yesterday, and two young toothache trees have already been transplanted elsewhere (read here).

This toothache tree has grown tall, but the curves in its trunk do not inspire confidence in its longevity, so perhaps we ought not be too upset about its destruction. Furthermore, this photo is a reminder that we ought to carefully stake young trees to encourage good upward growth.

This imperiled individual certainly can boast of having a unique trunk, with all of its bumps and spines. It will take some time for the young toothache trees to develop such interesting bark.

Here we see the reproductive structure of the toothache tree. You can find pictures of mature fruits on an older blog post, found here. Fruits from this toothache tree have successfully germinated in the soil of the arboretum, and, depending on the construction schedule, the developing fruits pictured here might have time to ripen and then potentially germinate.

A French mulberry (Callicarpa americana) grows directly next to the toothache tree, and a coral bean (Erythrina herbacea) grows on the other side of the French mulberry. Given its size and this species' tendency to resprout, the French mulberry could perhaps be successfully transplanted. However, the arboretum collection would best be served by focusing on nurturing the numerous seedlings that this individual has produced. Back in February, we collected five seedlings from this corner and transplanted them to other locations in the arboretum. More French mulberry seedlings remain in the leaf litter.

This French mulberry leaf is 5 inches long. It is floppy, fuzzy and very fragrant. Crush one and think about what you can detect. Some say that the strong fragrance serves as a natural mosquito repellent! 

Underneath, white hairs are visible on the French mulberry leaf.

 

Our greatest loss from this grouping of plants will be the coral bean (Erythrina herbacea). Over the winter, the root structure of this plant was examined, and it looked like it would take a backhoe to pull it up out of the ground―the trunk was large and bulbous. This plant is more than 10 years old and looks stuck in its place. It's unfortunate to lose this plant because it is a very handsome specimen, and, at this moment, it appears to be the only coral bean currently in the collection. There is one more coral bean, but it has not yet put up new leaves this spring.

 

Coral bean leaves are compound: this is one leaf with three leaflets. This leaf measures 7½ inches long.

 

Underneath, leaflets are a lighter shade of green. How would you describe the shape of the leaflet? Spade-shaped?

 

A black cherry (Prunus serotina) and its accompanying Carolina moonseed (Cocculus carolinus) must also be removed according to proposed plans. The black cherry was planted here in April 2019. You can read about its history on an old blog post found here. Pieces of Carolina moonseed resided in this sunny location prior to that time.

 

Taking a closer look at the black cherry, we see an irregular trunk. The trunk has the characteristic handsome bark, but the trunk is curved and divided. It never developed a straight form, turning into more of a shrub than a tree. So, it won't be sad to depart with this individual, especially since black cherry seedlings are commonly found in the leaf litter of the arboretum.

Caronlina moonseed is weedy in the arboretum. There are plenty of locations with Carolina moonseed, but there are few places where we would want to actually encourage it to grow. So, it might be a little challenging to find a new spot for our sign.

Carolina moonseed leaves are neat! Do you see an elephant's head pictured here? Two big ears and a trunk?

Interestingly, Carolina moonseed leaves resemble coral bean leaflets. On the left, we see a coral bean leaflet. On the right, we see a Carolina moonseed leaf. There are two different shades of green, but both the leaf and the leaflet have the shape of an elephant's head.

Underneath, the coloration is similar as well. Holding them in your hand, you can quickly tell them apart. The coral bean (pictured left) feels very delicate this time of year, as if it would easily tear or crumple. By comparison, the Carolina moonseed leaf (pictured right) is rigid. Also, underneath, the Carolina moonseed leaf has fine white hairs and feels soft to the touch.

 

Within this grouping of plants, five individuals are expected to be removed for construction and renovation on Mickle Hall. This is only one of several groupings that are imperiled by the proposed plans.

 

Back to School!

 

Ripening American beautyberry fruits brighten the yellowing, crispy August landscapes.

Pretty, purple fruits also signify back-to-school time. Centenary College is back in action―classes started last week!

 

Summer Update: Fruits and Flowers

There are a handful of immature fruits on the strawberry bush (Euonymus americanus), growing in the shade of our on-site native sweetgum (Liquidambar styraciflua). When the capsules open, they should reveal bright red seeds (do NOT eat).

The drupes of the Georgia holly (Ilex longipes) are ripening.

We have been watching the Mexican plums (Prunus mexicana) this summer. Numerous fruits fell early, but the branches are still heavy with ripening plums.

The fruits of the arrowwood bushes (Viburnum dentatum) are almost black.

Here we have a Gulf fritillary caterpillar conveniently stationed on its obligatory food source: the yellow passion flower vine (Passiflora lutea). The vine isn't long for this world.

The creeping cucumber vine (Melothria pendula) is producing fruits. These are said to be poisonous, so don't eat these.

 

 

 

 

In the arboretum collection, we have two kinds of French mulberry (Callicarpa americana). One produces purple berries; the other produces white berries. Above, we have an individual that produces the white variety--these berries won't turn purple.

The Louisiana catchfly (Silene subciliata) may not actually catch flies, but it certainly does catch the eye! They provide a bold dash of color in the late summer landscape. This nice patch is growing under a white oak (Quercus alba).

Summer Update

Trumpet creeper (Campsis radicans) has been flowering for a couple of months now. The water droplets in the photo are courtesy of the arboretum's sprinklers. Although, over the past couple of days we have had some rain.

Fruits of the persimmon tree (Diospyros virginiana) blend in with the leaves. They aren't ripe yet, but getting bigger.

The red buckeyes (Aesculus pavia) still have most of their leaves and their fruits are conspicuous.

The big-leaf snowbells (Styrax grandifolia) are covered in little fruits.

There is only one, but very large, nut on the little pignut hickory (Carya glabra).

Mexican plum (Prunus mexicana) fruits are ripening on the branch. Much of the fruit has dropped to the ground early.

Louisiana catchfly (Silene subciliata) flowers are a brilliant red. There are several nice patches scattered throughout the arboretum.

We're waiting on Magnolia grandiflora to reveal its bright red seeds.

Cones are hanging from the branches of the spruce pine (Pinus glabra).

The stunning fruits of the French mulberry (Callicarpa americana) bushes are typically a sign of the end of summer, transitioning to fall. There are approximately 10 significant bushes throughout the arboretum, with only one or two bushes showing off their ripening berries.