Anyhow, I did find a species that was new to me: Blacksenna. The plant has a scraggly, bushy appearance with an overall yellow-green look. The first one I saw was fairly small. A later one was much larger. An interesting thing about this plant is that it is parasitic on tree roots, pines in particular. Some authors state that it is harmful to young pines.
Piedmont blacksenna (Seymeria pectinata, Orobanchaceae)
I initially declared this to be Seymeria cassioides, but since (9/13/11) have determined that it is S. pectinata.