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). 

Gulf Fritillary (Agraulis vanillae)

Now that it's the beginning of November, you can find quite a few Gulf fritillary caterpillars on the Maypop (Passiflora incarnata). Coincidentally or not, a couple of years ago in 2023, we photographed these critters on November 5th! How's that for consistency? This year, chilly, autumnal weather seems to be on the verge of freezing the Maypop vine, so hopefully the little caterpillars enjoy the green foliage while they can. 

You can find the Gulf fritillary caterpillars on the prosperous Maypop vine, growing around the trunk of the deceased red cedar, near the Fitness Center. If you want to study the caterpillars, you will need to turn over some leaves―this one sits on top just for the photoshoot.

The other caterpillars were hidden under the leaves.

 

A couple of caterpillars were briefly relocated for a closer examination.

Examining the whole vine reveals the different sizes of caterpillars. As they grow, they molt, shedding their skin and becoming larger. These developmental periods between moltings are called instars (that's Latin for image, likeness, or kind).

 

The large caterpillar is more than an inch in length, while the tiny caterpillar is more than ¼ of an inch. That little fella is likely a newborn!

How long does it take the Gulf fritillary caterpillars to mature? The answer is about a month, with two or three weeks growing in the caterpillar stage and another week or two developing in the chrysalis.

Helpful Links

LSU AG Center 12-2022 Publication with info on Gulf Fritillaries 

Short Article from Loyola University in New Orleans on the Gulf Fritillary 

Maypop (Passiflora incarnata)

 

A delightful seasonal treasure thrives at the base of an eastern red cedar trunk. See our previous post on this plant here.

Purple flowers bloom on this bush-shaped vine. The flowers seem to be best during the morning hours.

These flowers, some wilting and some blooming, are awesome to behold. Note the sneaky anole, pictured center. That's a reptilian "photobomb."

What amazing colors and shapes are present here, part of a totally wild and unselected plant. And, looking closer, you can see a developing fruit.

And the 'great reward,' a green fruit shaped somewhat like a hen's egg, is hidden among the leaves.

The flesh of these fruits tastes tropical, sweet, and very light.

Visit the maypop before it gets gobbled up by the Gulf Fritillaries! We haven't seen any fritillaries in the arboretum yet, but they were spotted elsewhere in the Parish, presumably laying their eggs. We expect the spiky black-and-orange catepillars to eat these leaves.

Laurel Cherry (Prunus caroliniana)

 

Prunus is a famous, useful, and diverse genus. When you're "kind of a big deal," you typically have more problems come your way.

Here we see sap leaking from regularly-spaced wounds on the trunk of this laurel cherry (Prunus caroliniana).

This is likely the early stages of a condition arborists call "gummosis." The French botanist Auguste Trécul (1818-1896) was first to note, circa 1860, that a condition resulting in a superabundance of sap around a pathological zone could result from a variety of maladies. That name refers to the liquefaction of a tree's inner wood material and its leaking from wounds in the tree. This gummosis, or Gummibildung and even Gummifluss, as the Germans call it, can help protect a tree by isolating infected wood between hardened, protective plates. As it is really more of a physiological response than a disease itself, there is no singular cause of gummosis; it can result from insect damage, climatological stress, or infection by bacteria and fungi. 

Here we can see an old wound and the gummosis above it.

Back in June, this tree was placed on the docket for removal, primarily because of its significant lean. You can read that post here. The gummosis is not the reason for removal, but it did speed up the process. Enquiring minds want to know―what does the inner bark look like given the external gumminess? Is there a bug infestation or is it rotting? So the Faustian spirit urges, "Cut it down! Let's find out!"

 We are fortunate to have a volunteer ready to take its place. We'll stake that one and try to avoid the leaning tower of laurel.

In order to avoid destroying the smaller laurel cherry at the base, we first took out all the branches. Cutting most of the way through allowed us to extract the plant material slowly.

Here the tree has been separated into trunk and branches for easier disposal.

Here we can see the damage at the base of the trunk, which probably gave rise to the gummosis. Our working theory is that this damage was isolated and more-or-less healed by the tree. Later attacks by bugs or sapsuckers, in a vertical line from this damage, resulted in the tree leaking sap due to its proximity to the old wound.

The trunk ought to be round—and a crescent-shaped portion is clearly missing. What we don't see here is a lot of rotten material, a bug infestation, fungal infection, or other bad signs. The tree was, at least right now, apparently healthy despite the manifestation of gummosis. Nevertheless, we stand by the decision we made to cut it down, in large part due to the uncorrectable lean. In an unexpected turn, this newly cut lumber produced an aroma which corresponded precisely to a cherry soda.

All cleaned up and immediately replaced by the volunteer, who will reap great rewards in sunlight, nutrients, and water.

A Bacterial Gummosis of Cherries (1911) by F. L. Griffin

Gummosis of Prunus & Citrus (1911) by Ormond Butler

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.