Called "magic beans" by my family for 20+ years these are Lablab Purpueus, a climbing hyacinth. We've grown them upwards of 10' on a trellis. At its peak it will produce lavender flowers that eventually turn into soft seed pods. These pods turn crisp and brown and inside of them are more seeds you can harvest for friends! The flowers attract bees, butterflies and hummingbirds. Here is San Antonio they will grow and produce a second round of flowers and pods. They will die in a freeze. They will self sow. In this photo the hyacinth is to the right of the fall aster, you can see the young seed pods-they are purple.