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!

Hercules-club (Aralia spinosa)

As a result of far-reaching national policies and local edicts our college campus has been quiet for several weeks now. Minimal foot traffic means less of a concern for lawn maintenance and perfectly edged sidewalks. This moment has afforded us a rare opportunity to 'let our hair down' in the arboretum: the grass has grown high and our seasonal wildflowers have gone to seed. Also, opportunistic trees are overstepping their allotted portion of the landscape.

Little Hercules-clubs have popped up in the grass. This rampant growth has occurred over the course of four weeks. 

Such fast growth tells us that this shoot already has a well-developed root system, i.e., this is not a seedling.

Can you see the prickles on this Fresh green growth?

All new growth comes with its own armor.

Hercules-club (Aralia spinosa)

New leaves have emerged from the tips of the Hercules-clubs. Study the development from dormancy to full-vigor below. It's a 3-week transformation.

This is the top of a Hercules-club as of March 1st. It's a stick with odd ridges and spikes.

Two weeks later we see a little vitality: on March 12th, the apex has changed shape and turned green!

On March 21st, it's a completely different picture. We now have fresh, young leaves. These leaves still have a lot of growing to do. Hercules-clubs produce enormorous compound leaves.

New Leaves !

It's officially spring. Hurrah! A fine yellow dust imperceptibly floats through the air. Catkins accumulate in thick mounds. Bees bustle about in plum trees and redbuds. All the while Ivan Fyodorovich's sticky green leaves unfold.

The tips of the Hercules-clubs (Aralia spinosa) have started to turn green. This leaf bud was photographed on March 12, 2020.

Fuzzy new leaves of the smooth sumac (Rhus glabra) have emerged. 
Pictured March 12, 2020

Tiny, but quickly developing, heart-shaped leaves can be found among pink redbud flowers. 
Pictured March 12, 2020

Tree of the Week: Hercules-club (Aralia spinosa)

It's the first of March, and the characteristic 'March winds' were blowing in the arboretum today. The air was warm and wet and the clouds were hanging over head. Perfect tree planting weather!

It's also a good time for taking inventory. Today, a count was taken of the Hercules- club population.

This is a low, wet location in the arboretum. Typically, this area is thick with palmetto leaves. Recently, however, the palmettos were snipped back, allowing more sunlight and air flow. Since it's easier to move around in now, and the trees have not yet leafed-out, we took the opportunity to count the individual Hercules-clubs (Aralia spinosa). As of today at 4PM, there are exactly 30 clubs. A couple might be thinned out over the summer, but then a couple more might pop up out of the ground from the existing root structures. This species is very much at home in the arboretum.

Hercules-clubs are the skinny, leafless sticks, the 'devil's walking-sticks'. The clubs have light-gray bark.

The clubs are leaning toward the sun, away from the dense shade created by a nearby bald cypress.

These are very interesting landscape specimen, and no, they aren't pruned to look like that. Looking at these bare sticks, one wouldn't imagine that these little trees create some of the largest leaves in the arboretum.

Winter is the best time to appreciate the spiny, unbranched trunks.

Leaves will emerge from the top of the club in the coming weeks.

Tree of the Week: Hercules' Club (Aralia spinosa)

The Hercules' club (Aralia spinosa), our tree of the week, is especially noteworthy right now: its large fruit clusters are providing local birds a late summer snack.  

We have two groupings of Hercules' club in the arboretum. In 1989, Nick Leuck gathered Hercules' club seeds from Caney Lake, in Grant Parish. Those seeds were planted in the arboretum on the hill that slopes down from Hamilton Hall, where they successfully grew. A decade later, in the fall of 1999, two shoots were removed and replanted at the southwest corner of the lower pond. Today, only one young shoot remains at the original planting location, while approximately 20 shoots can be counted at the second location. Although the pond feature has since been removed, the area remains wet for a considerable part of the year, making it possible for the Hercules' club to thrive. In fact, it has been so successful there that overcrowding has become a problem over the past several years; removal of new trees has been necessary.

The photo above was taken at noon on a mostly sunny day. Dappled sun is hitting the grass and sidewalk, but the area under the Hercules' clubs (pictured to the left of the sidewalk) is densely shaded. This is a low area that often stays wet; this species seems to love it and new trees sprout there each year.

Of the approximately 20 individual trees, only a few of the tallest trees have fruit clusters, and they are out of arms' reach for humans.

This is only a section of a very large, bipinnately compound leaf.

This leaf was taken from one of the smaller Hercules' clubs. The leaf is approximately 26 inches in length. Leaves are much, much larger on the taller trees. 

Leaflets of the Hercules' club have serrated edges, and notice the little spines near the leaflet.

A ladder is needed to closely observe the fruit clusters.

Fruits of the Hercules' club are small, black drupes.

Numerous spines can be seen (and felt) along the trunk of the tree, giving it a threatening appearance, hence the origin of the common name 'Hercules' club'. Should a hydra appear in the arboretum, we would be well equipped to subdue it.

Detail of spines

This is bark from one of the largest Hercules' clubs. The spines are less noticeable, but still painful.

You can see additional pictures of the arboretum's Hercules' club here.

Check out the following links for more information about this species:
United States Department of Agriculture
Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter)
University of Florida
NC State University

Aralia spinosa

 

 Aralia spinosa is commonly called "Devil's walkingstick."