Tree of the Week: Arkansas Oak (Quercus arkansana)

 

The Arkansas oak (Quercus arkansana) is our tree of the week. There is only one Arkansas oak in the arboretum collection, and it has proved to be a resilient specimen. In May of 1996, it was collected as a seedling in northern Caddo Parish. It was nurtured in a pot for a year and then planted along the southern border of the arboretum. Two years later the little tree was dug up again. It was put back in a pot to avoid damage from the construction of Centenary College's new gym. In the spring of 2000, our tenacious Arkansas oak finally received a permanent spot in the arboretum, at the east corner of the Student Union Building.

 

Our tree of the week grows on a slope at the east corner of the Student Union Building. It is the tree with the noticeable lean in its trunk. We can't blame it for seeking the best exposure it can find to the scarce resource of sunlight.

The Arkansas oak has grown in direct competition with a Nuttall oak (Quercus texana), pictured to the right. The Nuttall oak is five to ten years older than the Arkansas oak.

 

From another angle, the Arkansas oak has a perfectly straight trunk, but the Nuttall oak, pictured left, still has a substantially thicker trunk.

 

Toward the base of the trunk, bark on the Arkansas oak is dark gray and very rough with no discernible pattern.

 

Above eye level, we see that the young bark has a different texture. It's still rough, but there are some smooth patches.

 

 

Arkasnas oaks have simple, alternate leaves.

 

 

alternate leaf arrangement of Quercus arkansana

Can you see the fuzzy texture on the twig?

Arkansas oak leaves vary in shape. Some resemble post oak leaves.

Unlike the post oak, the Arkansas oak is in the red-oak group. In this photograph you can see the bristle tips of the Arkansas oak leaves.

bristle tips of Quercus arkansana leaves

On November 7th, leaves are still dark green, but they lack their summer luster.

Leaves aren't big or showy, measuring under 4 inches in length, petiole included.

Underneath, leaves are visibly fuzzy, but do not particularly feel fuzzy.

One little acorn was found. This was the only acorn found attached to the tree. Perhaps there are more way up top, but none visible from below. A small number of acorns were found on the ground, but these could have belonged to the nearby Nuttall oak.

The small, round, striped acorn is half an inch long. According to the online literature, Quercus arkansana is a threatened species of oak. This little acorn ought to be planted!