When I was a student at Clemson University in the 1960's, this selection came in from the Bureau of Plant Introductions, a now defunct agency of the USDA. I planted it in the gardens there, which is now the South Carolina Botanical Gardens, and it withstood -8°F in the winter of 1984-85, with no damage. Of course one should realize that here in the South, even though we might reach quite low at times, it doesn't stay there as long as it does in some climates further north. It has the same great soft yellow flowers of the species, but since it is so cold hardy, it would be fascinating to know its provenance. These plants are probably close to 20' tall now and they are located up in the head of the duck pond, where they are somewhat shaded, but still flower well.