Montezuma Bald Cypress (Taxodium mucronatum)

The genus Taxodium has three living members. First and greatest is T. distichum, our famous bald cypress, which is found up and down the Mississippi embayment, the Gulf Coast, and the Atlantic seaboard from Delaware to Miami. Less well-known is T. ascendens, the pond cypress, which has a similar but much reduced range. Finally there is T. mucronatum, the Montezuma bald cypress, whose native range is mostly within Mexico and Central America, although a few of the Texas counties on the Rio Grande are counted as well.

Consequently, the Montezuma bald cypress isn't native to Louisiana or the southeastern United States. But having all three Taxodium species in the arboretum allows any visitor to see for themselves the dissimilarities that exist within this one genus.

There are two Montezuma bald cypresses in the arboretum collection. Way back in the '80s, Professor Leuck purchased their predecessors from Woodlanders Nursery (Aiken, SC), and he planted them in his yard on Albany Avenue in Shreveport. In 1994, Professor Leuck collected and rooted two cuttings from the Albany Avenue property, and in the fall of 1995, he planted the new trees on the periphery of the arboretum, near the lower level entrance to the Student Union Building.

The Montezuma bald cypresses are tucked in between the two staircases, flanking the doorway. Today, this is the entrance to the Post Office. Thirty years ago in 1995, it was the entrance to the campus bookstore. These trees have witnessed a great deal of change.

 

On the left side of the doorway, we see the southern-most tree. Its trunk is noticeably thicker.

 

On the right side of the doorway, we see the northern-most tree. Its trunk has a smaller diameter. Given that these trees are growing far north of their native zone, maybe its microclimate exposure to colder weather makes this the slower-growing specimen.

The staircase provides a neat vantage point, and it also allows us to see the leaves up close. Over the years, the lower limbs of the cypresses were removed so that pedestrians could easily move about without ducking all of those branches.

The soft, feather-like needles are arranged either in an alternate or spiralling pattern. The needles are mostly evergreen under good conditions, lasting until spring when they drop to make way for new growth.

Here we see approximately 40 pairs of needles on one branchlet. Unfortunately the number of needles varies quite a bit and isn't particularly diagnostic between species. The small blunted tips of each needle gave rise to the binomial species name; mucronatum refers to an abruptly angled point.

The southernmost tree has the thicker trunk, potentially because it has access to more sunlight. Its trunk has fewer lower limbs.

The trunk with the smaller diameter has more lower limbs. 

An additional photo, showing the relative heights of the two trees, would be useful here. Perhaps the thinner-trunked tree is taller. And we forgot something else! In the future we need to add photos of these trees' cypress knees... just kidding! They don't have any. This is typical of Taxodium mucronatum, and the absence of knees on a cypress should set off alarm bells that one isn't dealing with the typical bald cypress.

 

 Useful external links

US Forest Service page on T. mucronatum 

USDA Plant Database profile on T. mucronatum 

Post Oak (Quercus stellata)

 

Storm winds shook the trees of the arboretum last week, rustling branches and scattering loose twigs onto the ground. Although messy, this provides us with ample opportunity to study and compare a broad sample of leaves. Our big old mature trees tend to drop only their lower branches, leaving their fresh summer-time foliage out of reach. One such specimen is the aged post oak (Quercus stellata) standing near the Student Union Building. Its gnarly branches are way up high, but this week some of those upper story leaves were knocked out of the canopy.

From the ground, there were a lot of nice leaves to sort through. We see variations in size and shape, but the general shape description runs the same: roughly cross-shaped with five lobes. Although, does anyone else get the feeling that these leaves are reaching out for hugs?

This photo aptly captures one prominent quality of the leaf surface: shininess! With the leaves laying flat on the pavement, sunlight bounces off the leaf surface.

Standing the leaf up against the wet bricks takes away some of the shine.

Irregular leaves make tree identification difficult. But, if you already know that it's a post oak, you can appreciate the irregularity, and say, "Hey, that's an interesting shape! Cool."

An irregular, but still more-or-less recognizable, post oak leaf

Late Spring Flowers

Our long, rainy, pleasant spring officially concludes next week with the Summer solstice. In the photos below, we have two late-Spring flowers to compare. Some flowers are showy, with flashing color that catches the eye; others are small and nearly hidden. 

These bright yellow flowers are certainly of the former eye-catching variety. Golden St. Johns wort (Hypericum frondosum) has been part of the arboretum collection since 1990. It was initially planted near Mickle Hall. After about 20 years, surrounding trees and shrubs grew up around it, blocking too much of the sunlight, steadily reducing the size of the shrub. So a few years ago we took action to preserve the small remaining shrub. It's been transplanted to a more open area, along the gravel path that runs between the Fitness Center and the Student Union Building. 

  

Bees were so active on the St. John's wort that they were difficult to photograph! Slow down, ladies, you're too busy!

 

French mulberry (Callicarpa americana) also flowers in late spring. Clusters of tiny white flowers can be found on the numerous French mulberry shrubs spread out across the arboretum. 

These seemingly non-descript flowers introduce a contradiction when compared to their later product:  clusters of beautiful purple berries that brighten the sweltering August landscape.

More Arboretum Fungi

Our blessed rain and rising heat push the local mycelium networks to fruit. According to Jenny at the Mushroom Appreciation blog, for those of us in the Southeast during summertime: "The best time to get out in the woods is 2-5 days after a good rain storm. This is when most mushrooms will fruit. If you wait too long, you’ll have to contend with slugs and bugs who are looking for a nice snack." The arboretum's squirrel population might also be sampling the mushroom offerings. The photos below were snapped Saturday morning, and by Sunday afternoon, the mushrooms were gone or partially chewed!

Here we see a tattered member of Cantharellus, the culinary Chantrelle genus. Examining the Chanterelles of the US page at the above-mentioned blog, we feel confident that this yellow mushroom is edible, but since there are several candidates which match the color, shape and region, we can't make a firm ID.

This small, peachy colored mushroom growing in the grass is classified somewhere in the Boletus genus. Narrowing it down to a species is a daunting task. Beware the boletus rabbit hole! There's a 640-page book titled Boletes of Eastern North America released less than three years ago. Just move on. Which was an easy thing to do because no additional photos or examination were possible―it disappeared within 24 hours. By the way, Boletus is the Latin word for "mushroom."

There were several of these red mushrooms in a small patch under the pine trees near the Student Union Building. They are classified either in the Russula genus, commonly called "brittlegills" or the Lactarius genus (a "milkcap"). Probably the former. It's potentially Russula emetica, the "sickener". For loads of photos to compare, try making an account at Mushroom Observer.

Jack O'Lantern Mushrooms (Omphalotus sp.) TOXIC!!!

Copious rain and warm weather conspire to cause certain organisms in the arboretum to bestir themselves.

Countless students, faculty, and staff have walked past this post oak (Quercus stellata) on their way to and from the Student Union Building. It's an old, mature, on-site native oak, very much established before the construction of the Student Union Building.

Today, we notice something special. Something orange!

Something unusual and... infundibuliform. That's Latin for "funnel-shaped."

These mushrooms grow from the roots of the oak tree, feeding on lignin and dead material. Is the presence of mushrooms a good or bad sign for the health of the old oak? We have lost nearly all of our giant post oaks; this is one of the few remaining individuals. 

The following photos aptly shows a few defining characteristics: a funnel-shaped cap, orange color, and clustering.

From this angle, we see a bare stalk, true gills, and gill tissue that extends down onto the stalk.

We're as confident as we can be that this is in the genus Omphalotus, probably the Southern Jack-O-Lantern (Omphalotus subilludens) given our area.

This mushroom is noteworthy for two reasons. First, it glows green in the dark. Second, it's definitely poisonous. Don't eat it; you will deeply regret the experience.

For additional excellent photos of mushrooms in the same genus, check out the Texas Mushroom Blog by Dr. Alexey Sergeev, professor of mathematics at TAMU.

Shrub Removal: Gummi Berry (Elaeagnus multiflora)

This past week, we removed a long-time arboretum resident: one of our two Gummi Berry shrubs. One of the few intentionally-planted non-native species, these two specimens have been in the arboretum since 1997. That's nearly thirty years, older than most students on campus! When we covered these shrubs in 2019, both were healthy and prosperous. We last studied them in 2021, when they were providing some tasty treats to the Centenary squirrel population.

Entropy and time have worked together to compromise the health of one shrub. Ants and termites were present, chewing rotten wood and churning up the earth around the base of the shrub. Green leaves were still present, but three-quarters or more of the branches were bone-dry and naked. A colony of our small native black ants had taken up residence in its center. At this point, the main option presenting itself is removal.

Bare, brittle branches of the gummi berry (Elaeagnus multiflora) are pictured here. This shrub was planted as a pair, purchased from Mr. Sherwood Akin in 1997.

We see mostly dead branches, although there are a few green leaves.

During removal, the trunk of the shrub spontaneously split open, revealing plenty of rich dirt, termites, and ants where only healthy wood and roots should be.

The shrub has been converted into a large pile of branches, twigs, and poles.

Post-cleanup, only the small green sign remains, and it has since been moved over to the remaining shrub. 

We now have an opening in the landscape, and there are several months and two full seasons to think about what to plant here. 

 

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!