Mucuna pruriens? I grew them in a 20 gallon pot one summer. The vines grew and grew and grew and leapt from the support I provided to supports for other plants nearby, stretching across empty space like it could see where the next post or trellis was. The almost black form has attractive dark blooms and striking dark velvety seed pods. I really enjoyed it, but I would place it differently if I were to grow it again; somewhere neighboring plants would not be compromised.
