This plant had been on the Mystery Plants page for several years, described as a woody vine and with pictures only of the early Spring blooms.
In the Fall of 2006 I wrote Andy Cabe at Riverbanks Zoo about an article on Saw Palmetto that he had written for The State newspaper. In passing, I asked if he knew this one. Andy passed the query on to John Nelson at the A.C. Moore Herbarium at the University of South Carolina. John replied that it appeared to be hearts a'busting (Euonymus americanus) but that E. americanus was an upright shrub. When I wrote back that I was going down to the swamp to try to find it again to make sure of its vininess John quickly replied that "If this plant sets fruit, they are unmistakable: warty on the outside, and when ripe they break open revealing red seeds-"
As the sports guys say, "He nailed that one."
And on much closer inspection it was not a vine but a preternaturally spindly shrub so intertwined with smilax, catbriar, jessamine, grape, and honey suckle as to be thoroughly camouflaged.