Photo by John Nelson Dr. John Nelson

Each week The Columbia Star features an explanation and picture of a

mystery plant given by Dr. John Nelson, the curator of the USC Herbarium. To learn more about the Herbarium, call him at 777-8196. His department also offers free plant identification. www.herbarium.org

Recently, naturalists in SC have been taking a closer look at the shell middens we have along our coast. A shell midden is essentially a pile of oyster shells representing a trash pile, developed over many years by aboriginal people. My dictionary tells me that the word “midden” is of Scandinavian origin, and suggests a refuse pile, or perhaps less delicately, a dung–heap.

Coral catbrier, Smilax walteri The shell middens along our coast line are fascinating, and they feature unusual plant species. This is one of them.

It is an evergreen shrub, usually, or a small tree, although I know of one in Beaufort County that is about 40’ tall. This plant demands a bit of respect, as its trunk and stems are abundantly equipped with flat– based, gray prickles. The leaves are compound, bearing five to nine leathery, dark green leaflets. These leaves are also very prickly, and the midribs bear long, sharp stickers. Botanists, never at a loss for a clever term, will say that such a plant is armed. If you take a close look at the leaflets, you can see plenty of tiny, yellowish bumps. These bumps are actually plant glands that produce a number of pungent compounds which give the foliage and sap a powerful, aromatic smell.

Small, yellowish flowers are produced in the summer in clusters at the stem tips, followed by greenish, oily fruits about 1/3” long.

On more than one occasion I’ve encouraged my students to chew on a few fruits or crushed–up leaves. The taste and effect are astounding, and fortunately, temporary. The compounds within the plant tissues have a tingly, numbing effect on the tongue and lips. Because of this, the plant is sometimes called Toothache tree. Most of the adventurous students who had boldly agreed to chew the leaves agree that the taste is something like strong orange peel, and indeed, our mystery plant is a native member of the orange family.

If you'd like to see this plant, you might take a field trip along the marsh edges at our beautiful Huntington Beach State Park, which is located just south of Murrells Inlet, off US 17

Answer to last week’s mystery plant