I really need to keep waterproof boots and a long-handled hard rake in my car as I often find myself negotiating (unsuccessfully) roadside ditches to get specimens or take pictures of plants growing in or near those sources of water. In mid -September, I parked on the shoulder of the highway near Effingham and walked over to one of those ditches to get photographs of Mikania scandens growing over cattails. Then just last week, I was botanizing with John Nelson of USC’s AC Moore Herbarium and Extension agent Chase Smoak, and, there on a seep on the Smoak family farm in Clarendon County, we collected specimens from the numerous M. scandens vines growing there. This native plant is a member of the Asteraceae, the sunflower family, but doesn’t have the bright yellow ray flowers we associate with many of those family members. Also, this plant is a vigorous, climbing vine (scandens means climbing) that, when happy, scrambles up and over fences, shrubs and anything else it can twine around as it doesn’t have aerial roots, tendrils or spines. An herbaceous perennial, it completely dies back to the ground in winter but with comes back with the return of spring. The dull green cordate-shaped opposite leaves are an inch and half long and held on relatively long petioles. The flowering panicles are comprised of showy clusters of small, white (with a tinge of pink) tubular flowers. If you see this vine, do stop and watch as butterflies and moths and many Hymenoptera species feed on these flowers. To make Mikania scandens even more important in the native landscape, it serves as a larval food source for a number of caterpillars. If you grow this vine with other moisture-loving plants and give it a structure to twine and ramble over, you’ll have a showy and insect-attracting plant that flowers from early autumn until frost. Don’t be fooled by the name climbing hemp; the only reference to its use by native Americans was to treat itchy skin which might be why it is sometimes called louse plaster. Reports that in Hawaii and other Pacific Isles this species of Mikania is invasive are now thought to be a case of mistaken identify with another species, M. micrantha. With the common name of mile-a-minute vine, M. micrantha is one of the top one hundred global invasive pests and unfortunately was found growing in Florida in 2009.
Mikania scandens, Climbing Hemp
If this document didn’t answer your questions, please contact HGIC at hgic@clemson.edu or 1-888-656-9988.