Tree of the Week: Mockernut Hickory (Carya tomentosa)

Our tree of the week is a volunteer mockernut hickory (Carya tomentosa). All photos below were snapped on June 7th, 2020.

This mockernut grows in full sun on a grassy slope north of Cline Hall. An exact age isn't found in the catalogue; however, we know that it has been in this spot since at least 2008. We also know that it germinated on the grounds of the arboretum and was subsequently dug up and transplanted to this location. Its parent was an on-site native tree that has since departed.

Getting up close, we see fuzzy twigs and petioles, which help us identify the mockernut.

If the month of June brings you into close contact with a mockernut,  you might spy large, rounded fruits.

Fruits appear at twig apices, hidden by the compound leaves.

A small branch was snipped for inspection.

These fruits are immature, but already quite large. Mockernut fruits ripen in the fall.

Twigs are unmistakably fuzzy! Also, note the lines across the rounded fruits.

Mockernut leaves are long. From the branch we snipped, the largest leaf measured more than a foot in length.

Here we have seven yellow-green leaflets. Note the pointed tips and size variation in leaflets.

Underneath, leaflets are pale and fuzzy.

Zooming in on the leaflets we see a fine serration. Other individual mockernuts might have coarsely serrated leaflet margins.

You can see pictures of fresh new leaves here.

For more information about this species consult the following online sources:

United States Department of Agriculture
Fire Effects Information System (US Forest Service)

Tree of the Week: Native Pecan (Carya illinoinensis) Part Two

A blindingly hot summer day poignantly reminds us of the presence and indisputable value of a mature tree. Our tree of the week, the native pecan, is one such specimen. It's pictured in the photo above, working in concert with other native gems to offer a reprieve, however brief, from those intense midday rays. In our previous post, we talked about its known history, growing conditions, bark and fruit. This week, we are recording specifics about those shade-providing leaves.

Our native pecan (Carya illinoinensis) has a favorable reputation as a shade tree. It's handsome and a hardy native with large leaves that provide significant shade. However, in the fall, invectives against the tree might be hurled when these big leaves begin to pile up on the lawn.

A few leaves were snipped for inspection. Theys are long, each measuring approximately two feet in length, including the petiole.

Native pecan leaves are pinnately compound. Each leaf is composed of an odd number of dark green lanceolate-shaped leaflets. The leaf under examination possesses 15 leaflets, which vary in size. This leaflet measures 6 inches in length.

Another leaflet measures 7 inches in length.

Leaflets have pointed tips and serrated margins.

Underneath, leaflets are pale green.

Leaflets have an asymmetrical shape.

Native pecan petioles are long and feel fuzzy.

While still attached to the tree, petioles alternate along the twig.

Twigs are fuzzy, too.

You can find additional information about this particular native pecan here.

Tree of the Week: Native Pecan (Carya illinoinensis) Part One

This time we have a project spread out over two weeks: a thorough look at one of our native pecans (Carya illinoinensis). It's pictured center.

A precise age hasn't been determined for this native pecan. Some time before 2004, it volunteered in this spot, on the north side of the Fitness Center. Based on the arboretum catalogue, we presume it to be a hybrid from the neighborhood. But which other species did the native pecan hybridize with? Hopefully in the future we can resolve this question. This week we are recording information about its growing location, bark and fruits. Next week we will take a look at the leaves.

This native pecan has been successful in a relatively dry location. It grows towards the bottom of a steep slope. During heavy rains, water quickly runs down the slope, without accumulating in this location, and until last year, this spot has been without regular irrigation. Native trees are often quite hardy.

Rough, flaking, light gray bark covers the trunk.

Unfortunately, the handsome trunk bears the depredations of the yellow-bellied sap sucker (Sphyrapicus varius). The native pecan is not alone. We seem to have a healthy population of sap suckers. See Quercus lyrata and Ulmus rubra.

Looking up the trunk we see significant damage to branches as well. Large portions of bark have been removed from multiple limbs. Who is the culprit here?

We do not have photographic evidence to prove anything, but nonetheless we will move forward with accusations. It's the squirrels! They have a reputation for causing severe damage to tree bark. Reasons for the behavior are under investigation. Check out Joe Boggs' article on that subject (here).

Now, let's turn to the good news: we are seeing immature fruits on this volunteer pecan tree! This is of special note because the mature fruits will give us further clues concerning the lineage of this volunteer.

Will these fruits ripen into delicious pecan nuts? Or will we end up with something flattened and bitter, resembling the fruit of the bitter pecan (Carya aquatica)? Hopefully these fruits will ripen over the course of the summer so that we can get to know more about this volunteer.

Consult the following for more information about our native pecan:
United States Department of Agriculture
Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter)
University of Florida (IFAS Extension)

Tree of the Week: Nutmeg Hickory (Carya myristiciformis)

The nutmeg hickory (Carya myristiciformis) was previously featured on this blog for its shadiness. You can read more about its history and view its summer-time glory here. This time of year, our nutmeg hickory is of special interest for its nuttiness.

The nutmeg hickory is pictured center. It was purchased from Woodlanders Nursery (Aiken, SC) and planted in 1990. It's growing at the northern edge of the arboretum, between Hamilton Hall and the Student Union Building. In this photo, we see the ground sloping downwards toward the drainage channel, which lately has been moving no small quantities of water.

From this angle, we can see the ground sloping upwards toward Hamilton Hall. The nutmeg hickory grows mid-slope at the corner of a concrete drive.

At the end of December the nutmeg hickory is leafless and fruitless. There isn't anything blocking the view of its straight trunk and upwardly reaching branches. For a comparison, study the Shumard oak (Quercus shumardii) pictured left. The Shumard's branches stretch out horizontally.

Nutmeg hickory branches are angled upward.

After a brief kicking-about around the tree, 21 fruits were collected from the leaf-litter. Let's talk about this fruit in detail. The binomial name of the nutmeg hickory, Carya myristiciformis, means something close to "nutmeg-shaped hickory." If you compare a nutmeg to one of these hickory fruits, you will see why. They are light-brown in color with darker stripes.

Nutmeg hickory fruits are round, but not spherical. They are elongated with pointed tips. These nuts measure more than an inch in length. They measure 7/8 inches in width.

The darker colored nuts appear to have been gnawed on. Unfortunately for you and I (and the local population of arboreal rodents), they do not resemble a nutmeg in taste, fragrance, or value. The resemblance is in shape only.

For the purposes of observation and appetite, all 21 nuts were cracked open. The finest 12 specimens are photographed above.

The shells are impossibly thick, explaining how the nuts could have been gnawed on and abandoned unopened.

Nothing edible was found inside any of the nuts.

Foraging for an afternoon snack was a bust. However, a new skill was learned: how to crack a hard nut. This little sledge hammer did the trick. Each nut required approximately 3 light taps.

Black Hickory (Carya texana)

Late in August, we can appreciate the very large fruits of the black hickory (Carya texana).

Fruit and twig

Fruit detail

Nutmeg Hickory (Carya myristiciformis)

Compared to last year at this time, the nutmeg hickory has fewer fruits.

Fruit with attached compound leaf

Fruit detail

Tree of the Week: Bitter Pecan (Carya aquatica)

This past spring the bitter pecan (Carya aquatica) was the last tree in the arboretum to leaf-out; this should be noteworthy, given the number of species involved. We discussed this issue in a 'tree of the week' post back in May. You can find it here. At that point, the light-green leaves were still stretching out, and they were accompanied by catkins. Today, in the latter part of July, the mature leaves are providing ample shade, and we see large, developing fruits.

The fused-together clump of four bitter pecan trees is pictured center. Their combined canopies provide luxuriant shade. Shortly past noon on a full-sun day, very little light is hitting the ground under these trees. The white light of full-sun exposure can be seen in the background.

The large, compound leaves are catching all of the rays for us.

Among the four bitter pecans, we see some intraspecies variation in the leaves. We see both rounded and pointed tips on leaflets and we see leaflet margins with varying degrees of serration. Differences aside, the bitter pecan leaves are pinnately compound with 9 or 11 leaflets.

Leaflets are lighter underneath.

The leaflets are also fuzzy underneath and along the stems and twigs.

Fuzzy leaf stems alternate along fuzzy twigs.

If you look closely, you should be able to see a few of the peculiar fruits.

The greenness of the unripe fruit blends in with the surrounding foliage.

This is a cluster of three bitter pecan fruits.

Bitter pecan fruits are large and bulbous, but also flattened with four noticeable seams. At this stage of development, they measure approximately an inch in length. The insides are soft, watery, and contain a pressurized sac that will eventually develop and harden into a recognizable nut.

Glossy, dark-green leaves and unripe, light-green fruits of the bitter pecan