It is a climber, but the styles (free, not exserted) do not suggest a connection with the Synstylae species.
The leaves have pronounced veins beneath.
It is native to a region that is also home to R. laevigata, so maybe hardiness would not be expected. Even so, a climbing cousin of R. roxburghii would be an interesting acquisition.

http://www.fairfun.net/tour07/China/flora/flora.htm
The photo does not indicate the clusters shown in the drawing.

And another photo shows simple sepals.
