One of the nicest things about the Riverbanks Botanical Garden in Columbia is the assortment of wild habitats present around the formal gardens. These wild settings are perfect for field trips for our botany courses and are dominated by steep hardwood forests, but there are plenty of places where you can find plants more accustomed to open, rocky places. Like this one.
Our Mystery Plant is a native member of the mint family and it is somewhat woody, especially toward the base. Of course, the leaves are opposite, like everything in the mint family. Its foliage is characterized by a strong, musky sort of sweetness. A number of aromatic compounds are made in the leaves and stored in the various glands present on the leaf surface. (This is where the fragrance comes from.) It’s a very characteristic, smoky scent, and, to me, doesn’t smell like anything else. Definitely not “mint;” some people will say it’s stinky.
This brings up a matter about understanding plant families. Sometimes when we botanists speak of the mint “family,” listeners often infer that all the members of the family are mint, which isn’t so. The mint family, of course, is a huge one with many thousands of species. The true mints are members of the genus Mentha. Referring to a plant family by its common name, such as “mint” family or “sunflower” family is a bit troubling to a stickler like me who would prefer using the scientific names Lamiaceae, and Asteraceae.
You could (and can) just as easily refer to the mint family as the “basil” family, just like the sunflower family could be, and sometimes is, called the “dandelion” family. It’s just that the scientific name of the family removes all doubt as to what is being discussed.
Anyway, our Mystery Plant has its flowers borne in a series of compact, rounded heads situated at the top of the flowering stem. At the base of each of these heads, there are a number of very conspicuous pinkish bracts, and these are heavily dotted with tiny golden-yellow glands. The flowers themselves are showy and creamy yellow; the corolla is tubular with a very dramatic upper lip that arches over the lower lip. Inside the corolla tube will be two long stamens. The slender style, which is forked at its tip, can be found in there, too. All sorts of insects love the flowers – bees, butterflies and wasps are frequent visitors; even hummingbirds stop by.
This species is widespread in eastern North America from the Atlantic coast well into the prairie states. In South Carolina, it may be expected in every county but is most frequent in the coastal plain or sandhills, usually on sandy or rocky soil. It’s starting to bloom now, and sometimes you can find big patches of it. It has a number of relatives, such as bee balm and bergamot, most of which are very attractive and useful in gardens. Answer: "Horse-mint," "Spotted bee-balm," Monarda punctata
John Nelson is the curator of the A. C. Moore 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 www.herbarium.org or call 803-777-8196, or email firstname.lastname@example.org.