Scarlet runner beans.

[PhilaGardener]

If you want to save seed, pick a plant or two and let the pods mature and dry on the vine like any other bean.

I've grown both Scarlet Runner and IWK here in the mid-Atlantic - both seemed to shut down production in hot Summer months, but then picked up again in the Fall when things got cooler.

For Folks in SoCal or FL (maybe Gulf Coast to TX), runners have the potential to perennialize in very mild climates. You might see if they come back next year.