2022 Acorn Watch: Overcup Oak (Quercus lyrata)

 

This week in the arboretum, check out the developing acorns on the overcup oaks (Quercus lyrata). There are four overcups in the collection, spread out across the arboretum, and each one has at least a few acorns. The specimen pictured below has more than its fair share.

We discussed this individual back in August. At the time, the tree was covered with a profundity of immature acorn clusters, and the individual acorns were mostly concealed by the large caps. You can find those pictures here. Today, as we see from the following images, the acorn itself is visible and the caps vary in size.

This particular tree makes studying acorns a pleasure. Can you see how the lower branches nearly touch the ground as it slopes upward toward Rotary Hall? And there are acorns on these lower branches! No ladder necessary.

Some acorns are solitary.

And there are several clusters as well. You can easily maneuver the branches to study the acorns and appreciate the different textures: the cap is very bumpy, while the acorn itself is smooth.

Immature overcup oak acorns, photographed October 9, 2022

With so many immature acorns to examine, we can see variations.

We snipped two acorns to take measurements and to show the variation in cap shape. These are large fruits, and we see in the above photo that they are already more than an inch in length. The caps cover different proportions of the acorn. The cap on the left nearly engulfs the whole fruit.

2022 Acorn Watch: Post Oak (Quercus stellata)

 

Today is the first day of fall, and we have good and bad news about post oak acorns.

 

Back in June, we were happy to see nice clusters of acorns developing on the small post oak (Quercus stellata) growing near Cline Hall. In the above photograph, we see five acorns along the branch. These were easy to see from the ground. You can find more photos on the blog post found here.

Unfortunately, on the first day of autumn, the acorns, at least the ones on the lower branches, are hard to find, and they do not appear to be on schedule for proper development.

 

This is one of the few acorns that can be found while standing on the ground. We see a cap with only a  glimpse of the green fruit. Compare this acorn with the fruits in the below picture.

These three acorns were found on a different tree―an on-site native post oak growing on the outskirts of campus, near Centenary Boulevard. The green fruit is rounded and signficantly protruding from the cap. So, the good news is that the elderly population of post oaks will provide acorns for a germination project.

 

2022 Acorn Watch: Blackjack Oak (Quercus marilandica)

 

Back in July, there were several clusters of immature acorns on the lower limbs of the arboretum's senior blackjack oak (Quercus marilandica). Now that it's September, we only see a few scattered immature acorns on the lower branches. Below, we have three pictures illustrating the change.

On July 3rd, we saw a cluster of five immature acorns. This is only one of several clusters that were easy to examine while standing on the ground. You can find more photographs on the July blog post, found here.

In the middle of September, while standing on the ground, we see a few single acorns and only a couple of small clusters. In this photograph, there are two nicely developing acorns and one tiny, perhaps non-developing, acorn. A ladder was not used to investigate further up the tree.

In this photo, we have one developing acorn and a small non-developing acorn. While it's unfortunate that we do not have a better selection to examine, it's nice that there are some developing acorns to study. And these are neat little fruits! Can you see the orange fuzziness on the green acorn? Hopefully the ones that remain will continue to develop uninterrupted so that we can photograph the final product.

Pokeweed (Phytolacca americana)

We have another pokeweed update. This is a comparative post, showing, once again, how fast this weed grows and changes. Around northwest Louisiana you might come across a pokeweed plant that looks like a four-feet tall shrub with pink stems, covered in dark black round fruits. Those big pokeweed bushes are older; they are growing from an older root system. The pokeweed plant pictured below is young. It volunteered sometime recently, perhaps even this summer, in a wet, sunny location near the arboretum drainage channel. It has quickly taken root, grown, and produced fruit. 

 Remember ― all parts of this plant are considered poisonous. 

This is the pokeweed on August 30th. We see a few white flowers and developing fruits. We see a little pink on the stems.

On September 11th, the stems are now hot pink and there are several ripe fruits. It's a very interesting  specimen! This little plant is also still producing new flowers. Perhaps this will be a permanent fixture in the arboretum landscape.

Tree of the Week: Shumard Oak (Quercus shumardii)

Acorn Watch 2022 continues with a look at a volunteer Shumard oak (Quercus shumardii). This tree entered the catalogue some time before 2012, but its exact age is unknown. However, we know that it is old enough to produce acorns!

 

For the photoshoot, our Shumard oak is wearing a pink sash. The ribbon truly brings out the bumpiness of the ridges, don't you think? The pink ribbon is 4 feet off the ground, and at this height the trunk has a circumference of 21 inches.

 

As we see in the above photo, the pink flare helps us pick out the Shumard from its surroundings. Even though it stands near a sidewalk, the Shumard is easy to miss. All of its lower limbs have been removed, so we only see the trunk at eye level. Both the light pole and the emergency call station draw our gaze away from the trunk of the tree.

 

The Shumard oak grows toward the top of a gradual slope. It competes for sunlight with two nearby persimmons. Two older Shumards are nearby, just north of this volunteer.

 

Leaves are dark green, simple, and lobed. The petiole is nearly 2 inches long, while the blade is approximately 6 inches long.

 

Underneath, leaves are a lighter shade of green and mostly smooth.

Taking a closer look, we see the characteristic fuzzy spots along the midrib.

 

This leaf measures about 4 inches across.

 

Leaf edges are bristly. In this snapshot, there are at minimum 10 bristles.

 

While standing on the ground, it is possible to see several large clusters of acorns; however, a ladder was necessary to take a few photos.

Maturing Shumard acorns, photographed September 4, 2022

 

The acorn cap looks flat, rather than rounded like a bowl as many other acorns are.

 

This acorn is already of a nice size, measuring over ½ inch.

 

Pokeweed update (Phytolacca americana)

The plant is about the same size as last week. Except for the fruiting part!

These alien-looking fruits are developing without interruption, and now we can see the characteristic pink stem.

To see what this plant looked like last week, click here.
 

Pokeweed (Phytolacca americana)

 

At the bottom of the arboretum drainage near the Fitness Center, an interesting, potentially poisonous weed popped up in a bed devoted to a few fringe trees (Chionanthus virginicus). The weed rapidly grew, started flowering, and producing fruits. That's a rapid colonizer.

This is pokeweed (Phytolacca americana), a local favorite, celebrated each year in Blanchard at the Poke Salad Festival. This was formerly a very important species in this area, so it's worth paying attention to. It volunteered in a sunny, wet location, next to the concrete channel that runs under the Fitness Center ramp. This is a relatively small pokeweed plant, only standing about two feet tall. Other individuals of this species can grow several feet high.

 

In the photograph, we see one long raceme with a few white flowers and two developing white racemes.

  

The green, rounded structures are immature fruits. They are expected to turn dark purple or black. Unfortunately, these photos do not capture the characteristic pink-purple stems. If our volunteer pokeweed stays in the game, more photos will be posted.

Tree of the Week: Burr Oak (Quercus macrocarpa)

As part of our Acorn Watch 2022 series, we check in on the burr oak (Quercus macrocarpa). Exactly one year ago, we discussed this individual. You can read the post here. There is something about this tree that draws our attention each summer. It's the acorns! They are huge! Last year at this time, the burr oak was dropping immature acorns. Today, we have a different story.

Imagine what people are missing when they walk past this innocuous tree. All of the lower limbs are removed, so you need to look up, to see the acorns.

We have multiple photos of large, developing acorns still attached to the tree. These are only the acorns that we could reach. Looking up, large acorns could be seen going all the way up.

These acorns appear to be developing very well.

The larger acorn is over an inch in diameter!

This tree is clearly doing well over an extended period to support multiple clusters of such large acorns.

Last year, this burr oak was dropping immature acorns. As of today, the burr oak acorns are still attached, still maturing. So, what's the difference? At the begining of the summer, we were interested in the drought issue.

Interestingly, last year, when the burr oak was dropping acorns, Louisiana had zero signs of drought.

Right now, in August 2022, Louisiana is drier overall, and Caddo parish is particularly dry, as it is the only parish with an area of 'Extreme Drought'. However, our burr oak sits comfortably in the yellow zone, merely 'Abnormally Dry'. So, there isn't too much of a difference between this year and last year regarding drought conditions. Something else must be determining the fate of the acorns.

 You can read our previous posts about the Burr oak here, here, here, and here.

Tree of the Week: Overcup Oak (Quercus lyrata)

Acorn Watch 2022 continues with a look at one of the arboretum's overcup oaks (Quercus lyrata). 

Our tree of the week is an overcup oak (Quercus lyrata), located on the south side of the arboretum, near Cline and Rotary Hall dormitories. As shown in the picture, there is much sunshine on the grassy slope near the dormitories, but under the oak tree, we have a shady spot. Unfortunately, our arboretum catalogue lacks specific planting information for this specimen, so we cannot say exactly how old it is, but this oak was certainly planted after 1995. It is roughly 25 years old.

Trees, especially oaks, provide excellent habitat for all sorts of critters, including transient kobolds. This one stands about 3 feet off the ground.

At roughly 25 years of age, this overcup oak is producing a large number of acorns. Here, developing acorns of two sizes are visible. The tiny ones are not on track for ripening this year and are expected to drop from the tree as immature fruits.

Despite some predation on the leaves, visible to the right, these larger acorns look quite healthy.

 To see our previous post from four years ago on this species, click here.