Share

Why Do They Call It a Gum Tree?

Posted: July 7, 2014

Learn about black gum and other tupelo trees.
Black Gum (Nyssa sylvatica) Drawing by William Paxton, 2014

Black Gum (Nyssa sylvatica) Drawing by William Paxton, 2014

My professor had just demonstrated the sharpness of his recently honed axe by shaving a patch of hair from his arm. He then handed it to me and asked if I would split a rather harmless eight-inch diameter log section. Since we had been making firewood from a recently felled red oak, I said, “Sure. No problem.”

I took a careful stance, wound up, and brought all of my prowess and strength to bear and expected to soon hand him the half sections. After the third attempt I stopped and looked at him, with his now big grin. I had just seen a sharp ax bounce off a chunk of firewood!

Well, it seems that black gum (Nyssa sylvatica) arranges its inner cellular structure in a series of spiral growth layers that reverse direction. And if you want firewood pieces, you had best have a saw. The structure doesn’t make the wood especially rot resistant or even give it a super high specific gravity – but it doesn’t split easily.

This is a tree that will germinate and grow in small groupings with a clean, well-formed, and symmetrically balanced youthful form. Anchored by their tap roots, they seem to bend to the influences of time, and by age fifty, all pretense of straight form is lost. It has a deeply chunky bark in old age, but seems to have an asymmetry to its chunkiness – with one side of the stem often more furrowed than the other.

I know of an open-grown black gum that I visit every year in early fall when the flowering dogwoods are starting to turn red. This tree turns a deep scarlet red that is enhanced by the smooth glossy surface of the leaves. With the setting sun as back lighting, it is well worth the trip. I think this is the reason that gums (also called tupelos) are now in the Cornaceae family (dogwood).

The small blue-black fruit occurring only on the female tree is a drupe with one rather large seed inside. After a heavy storm I came upon a large one over a parking lot at a friend’s home. The surrounding area was covered with enough of the fruits that I could sweep the lot and collect a bushel easily.

There seem to be only four of the Nyssa species occurring in the U.S. Most of them are in the South. At one time there was a small town called Gum Pond, which is now called Tupelo in northeastern Mississippi. This small town was Elvis Presley’s hometown. In Pennsylvania, we have black tupelo or black gum (Nyssa sylvatica). There is a swamp tupelo (Nyssa biflora) that occurs in the coastal plains from Delaware south to Florida and west to Texas, also up the Mississippi river valley to southern Arkansas and Tennessee. Don’t confuse this with the water tupelo (Nyssa aquatica) that occurs in the lower Mississippi delta and the southeastern coastal plain solely. White tupelo (Nyssa ogeche) exists in southern Georgia and northern Florida. With the common name of Ogeechee lime, this is a tree I would make the effort to seek out. Beekeepers take their clean hives to visit them, even if they have to leave the hives on their boats in the river. With this nectar the bees produce the much sought after Tupelo Honey. Don’t confuse these gums with sweetgum, Liquidambar styraciflua. They’re not related. By the way, the genus name of Nyssa comes from a mythological water nymph.

In Pennsylvania we don’t normally see other gums. The first one I ran into was in Ligonier, PA. At first I thought it was a willow oak, with its thin, elongated leaves. Only later did I discover that this normally southern swampland tree was Nyssa biflora (swamp tupelo), well out of its normal range. I also discovered another large gum tree in Latrobe, PA (on the campus of St. Vincent College). Year after year I visit this tree and it was always labeled “Gum.” One year, when all of the “normal” gum trees had turned scarlet very early and dropped their leaves, this tree was still holding its leaves of bright yellow in November! It was easy to look up and learn that Chinese tupelo (Nyssa sinensis) is “rare in private collections”… problem solved.

It was the name that got me started on this species in the first place. I read in Humor and Humus that the folks on Martha’s Vineyard had a beetle bung tree. To make this story short, a beetle is a mallet for pounding, and a bung is the spigot that is pounded into many sorts of cooperage for draining. On Martha’s Vineyard both these items were made from the rather scraggly black gums that grow on the island.

If identification is still a puzzlement, you might get some small satisfaction that even members of the International Wood Collectors Society can’t tell these species apart if handed a piece of the wood, even under a microscope!

Prepared by William C. Paxton, Landscape Architect and Consulting Forester