Mystery Plant! #757

John Nelson

Posted 1/19/24

By John Nelson

            The Father of plant taxonomy, Carl Linnaeus, probably had had a run-in with his editor, while working on his monumental Species Plantarum, in which he attempted to describe all the known plant species of his day. Editors, as we know, are sticklers for detail…and for brevity. Botanists, being a descriptive lot, like to describe things with lots of words. So all that Linnaeus was able to say about out Mystery Plant was “It grows in southern America.” And that is certainly true, but there’s much, much more! Perhaps this little essay can expand upon Linnaeus’s description.

(Photo by John Nelson.)

            This is a deciduous tree, losing every one of its leaves by the middle of winter. The leaves are usually long and skinny, not much more than half an inch wide, and up to about 4 inches long. One might think that these leaves look like they came from a willow tree. They are smooth along the edges, and during the summer, an attractive bright green, becoming tan  or even golden when autumn comes. It is a native American, found naturally from New Jersey south to northern Florida, occupying coastal plain as well as piedmont counties. It’s also a member of the flora up into the Mississippi River Valley, to southeastern Missouri, and then west to Oklahoma and Texas. It seems to prefer bottomland situations along creeks and rivers, but often finds its way onto higher ground, and often is a colonizer of old fields. As a tree, we say that it is medium-sized species, but individuals in the right sorts of places can become tremendous, well over 100 feet tall. Moreover, the crown of mature trees can be very wide-spreading indeed. Big trees will have bark smoothish in places, otherwise finely ridged or checkered, and gray. Acorns are produced: not a surprise. Each will have a circular cap about half an inch across, and the acorn itself is small (for oaks) and nearly spherical. The acorns are produced every year on the tree, but it takes 2 years for a given crop of them to mature and fall.

            This tree is widely grown outside its native range, and with good reason. Mature individuals are prized as shade trees along streets and in parks, and elsewhere. Individuals exhibit fast growth, especially in cultivated situations in the right places. This actually can be a problem, as really big trees along urban streets may cause adjacent sidewalks to buckle and crack. They tend to produce all those acorns, and then lots of falling leaves, which gripes a lot of people. Not me. That’s what oak trees do. If it’s a problem, get out your rake. Keep the leaf-blower in the garage.

            One last tidbit here. When Linnaeus described this tree, he only had a couple of herbarium specimens to look at, and apparently no specifics on where it grew. He thought that  the leaves looked like those of the well-known “Cork oak”, Quercus suber, which is native to the Mediterranean, and named “phellos” by the Greeks.

[Answer: “Willow oak,” Quercus phellos]

John Nelson is the retired curator of the Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the Herbarium offers free plant identifications. For more information, visit or email

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