Unripe Hickory Nuts in August (Carya spp.)

Three unripe hickory nuts are pictured below. The largest fruit, pictured left, is from the Black Hickory (Carya texana). It is pumpkin-shaped and measures approximately 2 inches in length. The fruit of the Nutmeg Hickory (Carya myristiciformis) is pictured center. It is egg-shaped, measuring less than 2 inches in length. The Bitter Pecan (Carya aquatica) nut is pictured on the right. It might appear sphere-shaped, but it is noticeably flattened (oblate) when held in hand. The bitter pecan nut measures approximately 1.5 inches in length.

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

Tree of the Week: Bitter Pecan (Carya aquatica)

It is now the first week of May. The bitter pecan (Carya aquatica) finally started to leaf-out. This is indeed the last tree in the arboretum to put out new leaves. Over the past couple of weeks concerned glances were cast in its direction. But today, things are looking good.

The bitter pecan is an interesting specimen in the collection. It is four individual trees that have fused together at ground level. Such a formation can be explained by the history of the tree(s). In 1996, seeds were collected by Jack Price in northern Caddo Parish, on Jimmie Simpson's property south of Gilliam. They were gifted to Ed Leuck, who successfully germinated the seeds and nurtured the seedlings. In November of 1997, five seedlings from a single pot were planted together in a low, wet part of the arboretum, near the arboretum drainage. Four of the five seedlings did very well. Over the past twenty years, four healthy, albeit cramped, trees have developed.

The bitter pecan is pictured center. It looks leafless compared to its verdant surroundings. But the bare limbs allow us to appreciate its rounded crown.

There are four thick, robust stems.

At ground level the trunks have grown together.

These four trees have rough, flaky, gray bark that splits into narrow strips.

Some of the branches are still without leaves, but we can see leaf buds.

On other branches, fuzzy new leaves and catkins have emerged.

This twig has new compound leaves, but no catkins.

Zooming in on the new leaves, we see that the leaflets have serrated edges.

The yellow-green catkins are still developing. They have yet to release pollen.

For more information about this species consult the following sources:
United States Department of Agriculture
Virginia Tech Dendrology
University of Florida IFAS Extension