French Mulberry (Callicarpa americana)

 

Toward the end of spring, we noted that the French mulberry flowers are without pizzazz (read here). The flowers are small and hidden and they simply do not dazzle.

The fruits, however, are wonderfully bright. Their sharp coloration is much appreciated in the August landscape. Some fruits are ripening now, while other shrubs are on a different timer, ripening through the month of August and into September. 

 

This shrub near the southwest corner of Mickle is covered in ripe fruits, but other shrubs in the arboretum have yet to begin the process.

Fruits are edible straight from the shrub, but they do taste better when used to make jelly. Yum!

Dewberry Picking in the Arboretum

Fruits on the dewberry vines have been ripening over the past two weeks. 

The large dewberry patch near the Student Union Building is the easiest place to find and pick berries.

It isn't necessary to walk through the tall, overgrown areas—just walking the perimeter you can easily pick a handful of berries.

The fruits do not all ripen at once, so check back every few days to pick a few more.

Ripe berries are dark purple or black. Yum!

Bayberry (Myrica heterophylla) and Southern Wax Myrtle (Myrica cerifera)

The genus Myrica has a worldwide distribution that covers Eurasia and the Americas. Its ripened berries develop a protective coating of real wax that, in sufficient quantities, can be extracted and used to make candles and other items. Because true wax has historically been a prized commodity, it was previously worthwhile to collect and boil gallons of Myrica berries to skim off their modest wax coat. Now that petrochemicals have replaced the functions of innumerable plant and animal products, the cultural and economic value of this genus has been mostly forgotten. 

In the arboretum, we have two species of Myrica on display: bayberry (Myrica heterophylla) and southern wax myrtle (Myrica cerifera). 

This is our small patch of bayberry (M. heterophylla). It was purchased from Woodlanders Nursery (Aiken, South Carolina), and planted in February 1998. Currently, there aren't any fruits available for inspection. Our bayberry persists, but does not thrive.

On the other hand, southern wax myrtle (M. cerifera) grows happily in the arboretum. In 1985, eight pots of southern wax myrtle were purchased from Clyde Gorum's Nursery (Shreveport), and planted in the newly founded arboretum. Over the past three decades, these plants have launched numerous invasions of the wetland area, attempting total colonization. Today, three of the original plantings remain, the rest having been steadily cut back to make space for other species. The suitabillity of this species to our local environment thus appears to be significantly greater than its M. heterophylla cousin.

The genus name draws on a Greek word, Myrike, with a complicated history. It's associated with the Greek Tamarisk shrub Tamarix smyrnensis. That plant is fragrant and waxy, and is known in Greece as Almyrike. The southern wax myrtle's species name, cerifera, means "waxy." So you might think of this plant as "double-waxy" or even "Waxy waxy."

In this photo, we see one of the original 1985 plantings. This wax myrtle shrub is located on the north side of the arboretum, at the top of the arboretum drainage, where run-off water is funneled from up the hill at the bandshell, dormitories and cafeteria. This shrub has changed shape over the years, and intermittently suffered some damage. Several of our native vines must be periodically snipped from its branches, and the wax myrtle's branches must be pruned back from the railing, as it stretches toward the open sidewalk, vying for more sunlight. Overall, the shrub is well-suited to this spot and has required very little maintenance. 

 

Having this shrub next to the elevated sidewalk allows for easy inspection of the twigs. And look, we see fruits! Rustling the branches also provides a pleasing olfactory experience. Think "bay."

Sometime around 2010, a southern wax myrtle volunteered in the western drainage channel next to a wooden footbridge, which has recently been rebuilt. 

The footbridge was rebuilt just last month, in October. It looks great!

Two arboretum guests hang from the southern wax myrtle shrub. 

Getting up close and personal with the shrub allows us the opportunity to spy the tiny fruits, which will otherwise go unnoticed. In silhouette we see the shapes of the leaves (lanceolate) and the berries which sit along branchlets.

These berries are pale, grey-white, and wrinkled. That's normal.

Each of these berries has a tiny wax coating, like an apple from modern grocery stores, except it's natural wax, not a petrochemical. If you find a gigantic stand of this bush at the correct time of year, you might be able to collect enough berries to make some candles.

External Links

University of Florida IFAS blogpost on Wax Myrtle

National Park Service page on Wax Myrtle

Mississippi Wildlife & Fisheries Department data sheet on Wax Myrtle

Extremely helpful page on the practical extraction and use of northern Myrica species' wax 

Our southern wax myrtle (Myrica cerifera) has something of a confused taxonomic history, as it is related to M. caroliniensis (you can read about that in a paper by Robert Wilbur). 

Solomon's Seal (Polygonatum biflorum)

The arrestingly-named Solomon's seal (Polygonatum biflorum) is a handsome herbaceous plant. Its obscure common name is well-paired with its genus name, Polygonatum (which comes from the Greek gonatos)  and means "many-kneed." Do plants have knees? What does all this mean? We won't dwell on the unanswerable. There are a few dozen species in the genus, but most find their home in East Asia, far from Caddo Parish, Louisiana. 

As far as names go, we have a problem; our current signage turns out to be inaccurate. The arboretum catalogue shows two collection dates for hairy Solomon's seal (Polygonatum pubescens), both dating from the '90s. In 1991, Professor Ed Leuck collected a few plants from within Shreveport's city limits, on Line Avenue. A healthy patch still grows under the origianl red buckeye plants. In 1996 Jack Price of Blanchard donated six pots. Those plants have thrived on the southwest side of the long wooden bridge that runs from the Student Union Building to Mickle Hall. This patch continues to grow out into the lawn. Plants were collected from the grassy area and then transplanted to other areas of the arboretum, resulting in two additional patches of Solomon's seal. So, there are four total patches of Solomon's seal, and the original two patches are marked with green signs that read 'Solomon seal (Polygonatum pubescens)'. 

This is a relatively new patch of Solomon's seal. In 2023, we relocated a couple of plants to this spot, alongside a young black cherry (Prunus serotina). The black cherry has since grown tall, shading the Solomon seal.

The fruits were noticed several weeks ago. 

Leaves alternate and have noticeable ridges or veins.

As the bell-like flowers of Solomon's seal descended daintily and prettily from the stalks, so now do the berries.

These fruits greatly resemble blueberries, although they are much more firm. Be careful! NC State Extension claims, "The berries, if eaten, are poisonous."

Dark blue round fruits measure less than ½ inch across.

 

Squeezing the large fruit opens the bright green interior, revealing numerous seeds. Seven seeds came from one fruit. Another yielded four seeds.

 

Looking at the current classification information for Polygonatum in the United States shows P. pubescens and P. biflorum are the two major species east of the Mississippi. However, a distribution map clearly shows that P. pubescens is not found in the Deep South; its homelands begin in the mountainous, cooler climates of Kentucky and Tennessee. Since the distribution map for P. biflorum makes much more sense in covering the entire eastern half of the USA, we needed to take a closer look at the plants currently growing in the arboretum.  

Descriptions for both species state the fruits are similar. Descriptions differ for flowers, leaf size and shape, and the presence of hairs. Since flowers aren't available in late summer, all four patches of Solomon's seal were studied for leaf size and shape and the presence of hairs. 

This egg-shaped leaf suggests P. biflorum.

These narrower, lanceolate-shaped leaves suggest P. pubescens. 

These leaves are from two different patches. Do we have two different species or different light-conditions? The top leaf was found in full-shade. The bottom leaf was found in partial shade.

 

 

Within the arboretum's collection, leaf size and shape suggest that we have two different species of Solomon's seal. However, the common names dwell on the presence of leaf hairs, and although the leaves varied in size and shape, no hairs were seen on any stems or leaves. All surfaces felt and looked smooth. 

This is the underside of the leaf. We see spots, but nothing fuzzy. 

The underside is smooth. Leaves and stems from all four patches were examined, and nothing resembling hairs was detected. 

Based on species distribution and the total absence of hairs, we shall change the arboretum catalogue to note that we have Polygonatum biflorum, rather than Polygonatum pubescens. And, in the spring, we must study the flowers to see if they can give us any other clue as to the correct species label.

 

 

For more information about this species, please consult the following online sources:

USDA Plant Database Info for Smooth Solomon's Seal

USDA Plant Database Info for Hairy Solomon's Seal

Flora of North America Species comparison for these two plants 

Plants of Louisiana

NC State Extension 

Spice Bush (Lindera benzoin)

Spice bush (Lindera benzoin) fruits are ripening in northwest Louisiana. The youngest spice bush in the arboretum collection has a surprising number of fruits.

 

In 2022, this spice bush volunteered among a grouping of fringe trees (Chionanthus virginicus). This photo was taken the following summer in 2023. At that time, this spice "bush" had one primary stem, suggesting that it might develop a tree habit.

 

Today, the spice bush looks decidedly more like a 'bush' than a small tree. In this photo, we see several distinct stems.

 

Our young spice bush is tagged. Not every entry in the arboretum catalogue has a sign―that would be too much clutter in the landscape. There are already two spice bush shrubs with signs in the arboretum.

 

Numerous fruits are hiding among the leaves.

Sitting *under* the shrub, it's much easier to see the fruits.

Fruits appear in clusters along the branch.

The bright red fruits are ⅜ inches long. According to North Carolina State Extension, the fruits are edible.

The large, green drooping leaves come to a point and the leaf-base is asymmetrical. Both leaf and fruit have a spicy fragrance.

Dewberry Picking in the Arboretum

At the end of April, dewberry (Rubus trivialis) fruits are ripening in northwest Louisiana. Dewberry is a weedy plant―it readily germinates and thrives in unmanicured areas, such as along roadsides or fencelines. It also volunteers in areas where gardeners don't want it. This makes dewberry a classic "nuisance plant" because it spreads rapidly and the vines are covered with prickles. However, this time of year, it can be a joy to find: the wild, black fruits are a lightly-sweet, flavorful snack. 

Dewberry vines volunteer all over the Centenary College campus. Most are unwanted, and they are pulled up or chopped down. In the arboretum, there are more than a few cultivated patches, and there is one really big uncultivated patch. Near the Student Union Building, we have a mini-wilderness area that has developed into one large dewberry patch. 

On Saturday morning, two arboretum guests, a brother and sister duo, sampled and collected dewberries along the edge of the volunteer recruitment zone.

Dewberry wasn't planted in this spot; it volunteered here and has thoroughly entwined itself among the trees and shrubs. 

 

These young people were able to quickly identify the fruits and pick them. Neither individual complained about the prickles—the fruits often appear above the vines, making it easy to collect the fruits without being harmed by the vine's armor. Having small hands with deft fingers and being closer to the ground are advantageous!

 

Not all of the fruits are ripe at the same moment. Fruits in this patch have been ripening for nearly a week.

The dark black fruit is ripe and ready to be picked.

The red fruits are very pretty, but these aren't ripe. Let those develop on the vine another day.

Brother and sister picked three cups of dewberries in about 20 minutes, and then moved on to investigate other areas of the arboretum. That's $45/hr worth of fruit. Not bad!

Kentucky Coffee-Tree (Gymnocladus dioica)

In our contemporary situation of free and easy global trade, yearly consumption of coffee beans amounts to almost 25 billion pounds. You can get a cup almost anywhere, anytime. But since Coffea arabica can only be grown in a relatively few environments, war or trade embargoes can easily cut off coffee supplies to most places on earth. Due to this problem and the recognized benefits of the drink, coffee substitutes have often been sought and utilized. Today we'll showcase the arboretum's Kentucky coffee-tree (Gymnocladus dioica). 

 

It isn't native to Louisiana. The map below shows that the plant is really a Midwestern fellow, with its distribution dipping down into the southeast. 

This map shows the current distribution according to the USDA-NRCS. The Kentucky coffee-tree (Gymnocladus dioica) does not typically grow in Louisiana. Since it can be found in central Arkansas, this species certainly deserves representation in the Centenary arboretum.

There are two Kentucky coffee-trees growing in the arboretum. There is a big one, and right next to its trunk, there is a little one, which is clearly waiting for one of the surrounding trees to die so that it might have a chance to grow. These two trees do not have an official entry in the arboretum catalogue. They are mentioned elsewhere, in regards to other plants, but their specific planting history is missing. In an entry for spiderwort, the Kentucky coffee-tree is mentioned: "Another large clump [of spiderwort] with the seedling Gymnocladus dioica, below iris bed in west floodplain, planted 1999." A Kentucky coffee-tree seedling was growing in a pot with spiderwort, and they were planted together in the west floodplain in 1999. So, the Kentucky coffee-tree is at minimum 25 years old. According to the Iowa University Agriculture and Natural Resources Extension, the tree should be sexually mature and fruit-bearing once aged 20-30 years. Interestingly, this tree came to our attention this week because we found an unusual seed pod in the leaf litter.

This seedpod was found in the west floodplain under the Kentucky coffee-tree. Since the species is dioecious, that means our tree is female, but where is the male? How was it fertilized? The pod was cracked open and one seed was removed. It was in poor condition, so it was discarded.

Two more fruits were found. One is significantly larger.

The larger pod has one seed.

It's a large seed, mearsuing approximately one inch across.

The seed is round and dark brown.

As with the Yapuon holly (Ilex vomitoria), the Native American Indians of the Southeastern Woodlands are reputed to have consumed a tea made from the seeds of Gymnocladus dioica. The paucity of consumer goods in colonial times, being a major issues for homesteaders and travelers, there has been interest in this tree's seed since at least the late 18th century. Some people employed the Kentucky Coffee-Tree as a coffee-substitute up to and possibly during the American Civil War, when a Union blockade cut off the Confederate States of America from international trade. It was greatly inferior to the alternatives, such as chicory and scorched barley, as an uncaffeinated coffee substitute. Experiments performed by John P. Spaeth and John W. Thieret in the earlier 2000s showed that although potable, this drink was generally squalid. While true coffee addicts would consider such a product little better than a criminal act, a hot herbal beverage is better than nothing on cold days and long nights. Let's now check out the specimen itself.

The Kentucky coffee-tree is pictured center. It grows in a heavily shaded floodplain. All lower branches have been removed, so it will easily be missed as "just another tree" unless one is looking for it.

The wish-bone shape of this tree is no doubt a response to growing in heavily-shaded conditions. This tree is clearly adaptable.

It was planted near a Pinus taeda, an on-site native. From its first planting in the arboretum, the Kentucky coffee-tree has had to compete for sunlight, leaning away from the looming pine tree. Alas, it's good to have friends, even if you have to share your place in the sun. These trees have known each other for a long time.

The photos below were taken during the winter months. They allow us a less-cluttered view of the landscape.

 Clumps of spiderwort (Tradescantia ohiensis) grow at the base of the Kentucky coffee-tree trunk. Spiderwort was planted at the same time as the coffee-tree.

Kentucky coffee-tree has gorgeous papery bark.

 

The tree has an irregular growth pattern, as noted above. Hopefully this will not lead to cracking and breaking in the future.

Additional resources:

USDA Plant Profile on Kentucky Coffee-Tree

Lady Bird Johnson Wildflower Center

North Caroline Gardner Extension