Hi again, Dr. Hill,
On June 12, this plant was growing in full sun in a ditch along a country road in an area straddling the piedmont and Fall Line. The leaves are long grass-like blades, like those of an iris. It appeared to grow in a clumping form, but there were a few stand-alone examples adjacent to it. Is it a native?
yes, it is a native. It is a Spiderwort, and most likely Tradescantia ohiensis which is a widespread species. A less likely possibility is Tradescantia subaspera, but I think that T. subaspera has hairs on the leaves and / or calyx. I don’t see any on your images. This is in the dayflower family, Commelinaceae, a monocot family.
I hope this helps.
Steven Hill, Botanist, SCNPS