Dear Dr. Hill,
This plant with clusters of very tiny violet flowers was growing in full sun along the road in the Piedmont of SC in June, 2015. Enclosed also is a picture showing it from afar, growing in a small loose clump.
this attractive plant is Heliotropium amplexicaule, the blue heliotrope. The flower with numerous corolla lobes is aberrant, as the flowers usually have 5 lobes. It often appears to be native, but it is actually an introduction from South America. It is in the Borage family [Boraginaceae]. You can find out much more about it here: http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-0605030c0f01/media/Html/Heliotropium_amplexicaule.htm
Steve Hill, Botanist, SCNPS