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. 

 

Scarlet Buckeye (Aesculus splendens)

The arboretum's only scarlet buckeye (Aesculus splendens) appears to be in its death throws. Leaves are absent and its limbs show evidence of decay, with patches of peeling bark. This tree was previously covered in a blogpost from 2021, and even earlier in a blogpost from 2018, alongside its old friend the peppervine (Ampelopsis arborea). Careful examination reveals some signs of life, but the outlook is grim.

This placard has weathered more than a few seasons. Our scarlet buckeye is, at minimum, 37 years old. It was purchased in 1988, from Woodlanders Nursery (Aiken, South Carolina).

 

You can find this tree on your right as you walk from the Fitness Center towards the Hargrove Bandshell.

 

We can see all the branches―they aren't concealed by leaves.

And up close the branches do not look good. Peeling bark opens the tree to attacks by insects and fungi, and it indicates internal deficiencies within the tree's health that make these problems more deadly.

 

A will to live is still present. Unfortunately, this tiny leaf is at the tip of a branch that already shows significant decay.

The trunk does not have any peeling bark.

And looking closely at the trunk, two green buds were found. This is one. Do you see it?

Zooming in on the trunk, we see new green growth.

 

This is the second green bud found on the trunk. Perhaps more will appear soon.

 

Although the prognosis is not good, the arboretum isn't a place to rush and cut a tree down―we're not in a hurry to determine the next step. Let's give the specimen a reprieve, and see what happens in the coming weeks.

Big-Leaf Magnolia (Magnolia macrophylla)

Last month, the big-leaf magnolia caught our eye with its large, drooping, creamy white flowers. On par with the American lotus (Nelumbo lutea) for the prize of "biggest flower native to North America," this rare specimen deserves more attention. We currently have three plantings of big-leaf magnolia in the collection, and all three would benefit from some spring-cleaning activities, like pruning and weeding. 

 

Two big-leaf magnolias are pictured here. There is a larger one in the center, and a smaller one is leaning on the right side of the frame. The smaller one was planted in 2009, while the larger one was planted a few years prior. Both were badly damaged in August 2020, during the storm winds from Hurricane Laura. In this photo, we see the work to be done: surrounding shrubs and vines are encroaching on the space allotted to the big-leaf magnolias.

We cut back wax myrtle (Myrica cerifera) shrubs to allow more sunlight for the magnolias. Virginia creeper (Parthenocissus quinquefolia), poison ivy (Toxicodendron radicans), and some grape (Vitis sp.) were all pulled from around the base of the skinny trunks. A few stalks of lizard tail (Saururus cernuus) were also snipped to increase signage visibility.

Despite being more than 15-years-old, these are still small trees, and they need help when it comes to competing with their more aggressive neighbors. And since this species isn't particularly robust, we are keeping both trees in the catalogue, rather than cutting down the smaller of the two. We don't want to cut the small tree for a couple of reasons: it doesn't take up much space, and it is our back-up plan or insurance policy if the larger tree dies. A falling widow-maker could easily cause such a fatality.

Water Locust (Gleditsia aquatica): Secondary Cleanup Operation (Updated)

As shown on a previous post, which you can read here, the arboretum lost an important tree this spring: our water locust (Gleditsia aquatica). The tree fell more than a month ago. Continued rainy, stormy weather has not allowed for a swift cleanup operation. Most of the damage, and specifically the hazardous parts, were cleared during the first week of May. More work remains.

Most of the water locust and broken yaupon holly branches were removed by the Centenary College grounds crew. Large pieces of the water locust trunk remain for observation. There isn't a hurry to remove the nicely shaped logs; however, the railing ought to be fixed soon to prevent an accidental stumble into the lower drainage basin. Note: the railing isn't meant to keep visitors out of the drainage basin—there aren't any 'off limits' areas of the arboretum.

As we see in this photo, there is a drop-off from the pedestrian area into the basin. The railing draws attention to the basin and prevents folks from haphazardly dashing off into the lower area. Also, a locust grew here, so there are plenty of dangerous spikes on the ground, hidden among the vines and irises.

Interestingly, when time came to saw the trunk that remained in the lower pond, fresh shoots were noticed. This part of the trunk was still attached to the in-ground root system.

Indeed, the water locust would really prefer to defy death.

Once again, the ground here is littered with nasty locust caltrops.

Here we can see why the tree fell. The entire root ball dry-rotted and turned to a spongy cork-like material.

Update: after a great deal of sweat and oil, the fallen trunk is gone. Only a series of blogposts remain.

Soon the undergrowth will expand to fill the empty space. In a year or two, this miniature glade will be choked out by undergrowth.

Our resident Arboretum Tabby is a great cheerleader and encouragement. "Good job," it says. "Just keep your distance. I'm feral."

Spring Storm Damage: Water Locust (Gleditsia aquatica) and Yaupon Holly (Ilex vomitoria)

This spring we have had quite a few significant rain events, thoroughly washing out the gravel paths of the arboretum, as well as noteworthy thunderstorms, with powerful winds, mangling and toppling trees in the local community. On Sunday, April 28th, a storm blew through the arboretum, nudging over a weakened water locust (Gleditsia aquatica). Since last fall, the water locust had been marked for removal due to its unhealthy trunk. A licensed arborist with an experienced crew would have been the preferred method of removal, as such planned, controlled events tend to result in less overall damage. The 'wait-and-see' strategy of tree removal has resulted in undesirable damage to surrounding plants.

 

Yellow caution tape was seen in the arboretum this week.

 

A large area was cordoned off using yellow tape to discourage pedestrians from getting too close to the fallen water locust (Gleditsia aquatica) and the mangled yaupon hollies (Ilex vomitoria).

 

The fallen water locust is suspended on an interwoven network of yaupon holly branches.

 

This is a major pathway through campus. There were perhaps several disgruntled, or at least surprised, pedestrians this week. No doubt they were annoyed with the necessity of walking around this mess. Of course, it was also Finals Week.

"Dead end! Turn around!" or "Halt! Frogs only beyond this point!"

 

Our fallen water locust was collected locally, in 1995, from Dr. Dana Kress's property on Cross Lake.

For nearly 30 years, the water locust grew happily in the 'lower pond' area of the Arboretum, surrounded by Sabal sp., Iris sp., Taxodium distichum, Aralia spinosa and a nearby Planera aquatica, as well as a Betula nigra.

A railing helped break the fall of the water locust.

A smashed railing. What do you think the impact sounded like?

The water locust has such interesting bark! Not only are its spines terrifying, but they also function as a trellis for green-briar vines.

Although its trunk was rotten at the base, the water locust remained alive all winter. Green leaves are pictured here.

Fresh green growth of the water locust.

The water locust fell on top of two groupings of yaupon holly, one marked 'male' and the other marked 'female.' Both groupings of holly sustained similar damage, and both are expected to make a full recovery.

This yaupon holly is marked 'female.'

The thick water locust trunk rests on the splitting yaupon holly.

This yaupon holly is marked 'male.' That's an important consideration for dioecious trees. Male yaupons won't make the pretty red berries!

This yaupon holly trunk is split and will need to be cut.

The two yaupon hollies will be just fine. Unfortunately we lost our only specimen of Gleditsia aquatica. Luckily, a seedling was growing in the leaf litter. Earlier this week we dug it up and potted it. Hopefully this volunteer will grow up quickly and be transplanted back into the arboretum, although it might be difficult locating a suitable spot for it. But where there's a will, there's a way.