Manihot grahamii / Hardy Tapioca / Graham's Cassava: a native of Eastern South America, from Brazil through to Argentina. I've done a quick web search and this has been successfully grown as far north as North Carolina. (This photo said it was taken in the Pacific NW).
Biltmore Estate, Ashville, NC. Yes there are castles in the US. This spectular Vanderbilt home is well worth the visit. The castle, rooms, gardens and even the converted dairy barn, now the winery are memorable.