Thank you for your answers, you both.
Do you think I could grow the Callerya here in Languedoc in a very hot wall (south faced) ?
I sowed seeds of Hardenbergia 2 or 3 years ago and they germinated well, but I lost them during the winter because I planted them outside with no protection against frost. That's a shame because I like it very much.
On the other hand, I think it would be ok for the Atriplex.