Hi, Dr. Hill,
This plant was growing in a partly shaded area along a country road in the SC Fall Line area on Sept. 7. The flowers are pink and the stems of the leaves are burgundy and the same color lightly marks the leaves. There were about a dozen plants, so it seems to be happy growing in those conditions. Thank you very much.
your plant is in the mint family, Lamiaceae, and is called Perilla frutescens. I like to use the common name shiso, because it is a vegetable used in Japan and Korea and probably elsewhere, but it has escaped in the USA and persists. Some consider it weedy. There are many varieties – a purple one is often seen as well. It can be quite common.
Steve Hill, Botanist, SCNPS