Our Grapes are Ripe! (Vitis rotundifolia)

Vines, especially huge ones, may be dangerous or considered unsightly. But if you look up...

You may notice delicious fruit!

This is a limited-time offer. These spicy muscadines will be gone soon.

You may find them on the ground or within arm's reach. Don't climb the tree, unless you're a rodent or marsupial, that is. The vines grow on an old, on-site native white oak (Quercus alba) that isn't as robust as it once was.

These native purple muscadines not only look gorgeous, they're tasty and a healthy snack.

 

Muscadine Fruits

This month in the arboretum, look for ripe muscadine grapes. You can read about this collection of vines in a previous blog post, here.

The darkest grapes should be easy to pull from the vine.

These are perfectly ripe.

These are large grapes with a strong, Welch's grape flavor, accompanied by a peppery after taste. The skin is thick and you will find one to four seeds inside.

Tree of the Week: White Oak (Quercus alba) with Muscadine Grape (Vitis rotundifolia)

The white oak (Quercus alba) is a valuable member of the oak family. This species provides wonderful foliage in the fall, and its fruits keep wildlife well-fed, as it produces acorn crops on a different schedule than the red oaks.

The species establishes well in the arboretum, with numerous volunteers. This is probably due to a combination of abundant moisture and the sloping terrain of the Centenary campus. A white oak will not tolerate standing water and its drought tolerance is not especially high. Like many plants it will, therefore, do best in places that have both good drainage and an adequate water supply.

This week, we consider a very large, old white oak. It plays host to our most beloved native North American grapevine, the muscadine (Vitis rotundifolia). While the vine is thriving and producing fruits, the tree looks to be in decline. The following photos illustrate both the declining health of the tree and the advancing success of the vine.

This photo was taken circa 2012. The white oak is pictured center. The old tree has a rounded crown, although not quite full. There is plenty of open-space among the branches. The muscadines form a bush around the base of the straight, white trunk.

From the photo taken today, we see that the white oak no longer has a rounded crown. In the interim several large branches have fallen from the left side of the tree, and several dead branches are visible. The trunk is obscured, as it has been swallowed up by the muscadines.

The muscadine vines cover the south-facing side of the trunk.

Looking upwards, we see the vines are well-established among the old, heavy branches.

But the vines aren't as thick on the west side of the tree.

The gray, rough bark is visible on the west side of the tree.

So, does the demise of the tree follow from the success of the vine? Are we to blame the muscadines for the declining health of the white oak? Has the vine 'strangled' the tree or out-competed the tree for resources? Probably not.

Old-age is another potential explanation for the tree's declining health. This specimen antedates the arboretum, so specific age is unknown, but it's obviously a very old tree, given its large size and the slow growth rate of the species.

Furthermore, white oak longevity might be dependent on a cooler climate (more continental/temperate than subtropical), which we are lacking in northwest Louisiana. The white oak has a very large range; it occupies most of the eastern woodlands in the US.  The species is very common in the state of Louisiana. However, the largest and oldest white oaks in the United States appear to be in the Northern half of its range, particularly the Ohio River Valley and mid-Atlantic seaboard of the New Jersey/Delaware area. The single oldest specimen lived in Basking Ridge, New Jersey, until it was cut down in 2017, after an estimated 600 years of growth. Our tree's declining health is perhaps due to the climate in the south, which is outside of the range of the champion trees of this species.

Enjoy the fruits of the vine!

Muscadine fruits are ripening this time of year. In November of 1997, Ed Leuck planted six seedlings around the base of the white oak. Two seedlings were acquired from Sherwood Akin nursery in Sibley, Louisiana. The other four seedlings were grown from seed collected from the Caroline Dormon Nature Preserve.

Muscadine leaves are toothed with a cordate shape.

The spherical fruits are thick-skinned and spicy. They are approximately a half inch in diameter.