Hi, Dr. Hill,
This pretty patch of very small yellow and orange flowers (each about 1/2-inch across) was growing on July 12 in a field along a country road in the SC Piedmont in full sun. Thanks!
your plant is one of several species loosely called St. Johnswort, but this is a native and not the introduced species that has been used medicinally. I am not 100 % certain which species this is, but my most confident answer is that it is Hypericum lloydii, which I have admired in the sand hills and piedmont this time of year. It can grow in dry areas, whereas most of the other possibilities, such as Hypericum galioides and H. fasciculatum, tend to like wet or moist low areas, even cypress swamps. The narrow leaves are distinctive for a group of southeastern US species.
I hope this helps.
Steve Hill, Botanist, SCNPS