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 

Osage Orange; Bois D'arc (Maclura pomifera)

As the bois d'arc is a dioecious tree, the arboretum catalogue is somewhat incomplete. The specimen we currently possess is male, and while males are certainly necessary to perpetuate the survival of the species, we get no fruit from them. The unique green fruit is the most noteworthy feature of this species, something that we would like to show to the Aboretum's guests.

After last winter's ice storm, the arboretum curator discovered a decrepit, sad-looking bois d'arc on a fenceline in Caddo parish, just north of Shreveport. Surrounded by a grove of invasive bamboo, next to an impromptu trash dump, and near an unfriendly pack of local canines, this tree has been lost to the knowledge of mankind for decades. Its presence on a property line is fairly good evidence that it was intentionally planted there. The arboretum curator only recognized the tree as a bois d'arc due to the presence on the ground of a solitary green fruit. Considering the extensive rot and overall poor state of this tree, that may be the last fruit it ever produces. 

Two to three months of cold winter temperatures are necessary for the germination of bois d'arc seeds. We definitely had such temperatures this year. After being collected, the fruit was tossed onto the ground outside, where it sat for the duration of January, February, and March. By the end of March, the fruit was black-and-brown, soggy, and infested with a variety of nasty critters. The seeds were painstakingly extracted with a knife and a pair of tweezers, yielding approximately 100, with an estimated half that number being left behind. This was a messy job. The seeds were washed and allowed to dry, then placed in a bowl of rainwater to set for about a week. After this, they were planted five to a container in potting mix. A couple weeks later with temperatures rising, young bois d'arcs are beginning to push up through the potting mix! We are pleased to see that the old tree has produced viable seed. Providence willing, these specimens will become part of the arboretum collection.

We have a flat of seedlings. About five seeds are sprouting per day.

Here we can see one larger sprout and another which still has the seed coat attached, still covering the cotyledon.

The bois d'arc is pictured center. Almost every visible leaf is from poison ivy or another vine.

Here we can see a few sprouts coming off the trunk, a feeble last attempt to get ahold of some sunlight. The bamboo is winning.

From this side, we have a better look at the trunk and its branches. The tree was able to grow in this location long enough to develop a thick trunk. Unfortunately, it appears that the bambo has outcompeted it in recent years, but, luckily, we found one of its fruits and have thus far had success in our germination project.

Mayhaw Success!

 

These are the arboretum's four mayhaws. This is definitely the most famous, at least in our region, member of the genus Crataegus.

Right now in the arboretum we are happy to see pristine-looking mayhaw fruits, something that we haven't had for more than 5 years.

Not only do we see red-ripe fruit, we also have green fruits coming in behind them. Look how healthy the leaves look! A new era is dawning.

All efforts to control the arboretum's cedar apple rust were unsuccessful. In 2018, we undertook to spray the mayhaws with a fungicide (you can see photos of that here). We made multiple applications and documented the development of the cedar apple rust galls. As previously explained on this blog, we ultimately made the decision to remove the eastern red cedars (Juniperus virginiana) in favor of the crabapple tree and various haws. This process was carried out over several years, as documented in 2021 and 2023.

What we're observing now with the improved health of the Mayhaws (in both leaf and fruit) is that we made the correct decision, insofar as our goals are now being achieved.

Nevertheless, we're not entirely out of the woods. These three groups of mayhaw fruits, all collected today, show that it may be a year or two before the disease is entirely purged. The majority of fruits we observed today were healthy (see far left duo). Some had a small blemish.  A few have been transformed into monstrous mutants, reminding one of John Carpenter's 'The Thing' (see center green fruit, studded with pink horns). If these tell you they're "just fine" or "all better," don't believe them. Finally, as pictured on the far right, we can see that some fruit simply withered on the tree and failed to grow at all. This was a failure for the cedar apple rust as well, as it requires the developed fruit to spread the infection.

This is unsettling to look upon, but we feel obligated to document it. Yuck.

While carefully examining the trees for new fruit, several dead branches were noticed, so a little pruning was necessary. When working around mayhaws, watch out for spines! These branches will poke you.