Wild sweet pea vine?
Is this some sort of wild pea vine? It's perennial. Right now it's got nothing to grab onto, so it's in a sort of loose shrub form. The last two years it was winding around the weeds in this area. It flowers from June or July til early autumn. It's very hardy (has been weed-whacked to the ground several times and always comes back), but it seems to be well-behaved as it hasn't really spread past this spot, which is right by the road. I tried to identify it last year, and the plant that looked most like it is said to naturally occur on sandy areas of the eastern coast, so that can't be it. I can't seem to locate the identification page I was using last year, though.
Is this something that could be moved and trained on a trellis? Or is it too aggressive?
Pictures are entire plant, closeup of leaves, closeup of flower, closeup of unopened buds.