A couple of years ago a potted vine came in to Fern Valley from a nursery that produces plants from seed collected from native plants in the state of Maryland. It was a nice perennial in the pea family and when it flowered, the blooms looked a lot like this but they were subtly different. The label read: "Centrosema virginiana or Clitoria mariana"; they weren't certain of the identification. Well, when it flowered, Joan and Alan (USNA botanist) looked at it and concluded, to my great relief, that it was Centrosema.
All was well except that I am having a difficult time finding a site that suitably displays it, provides good growing conditions, and in which it won't be overrun by more vigorous elements. Anyway all was well until last week when we found abundant examples of Clitoria in Bibb County Alabama. We collected a good amount of seed and will doubtless be able to produce nice plants in the next year or two. Maybe we can label it so well that no one will ask me its name, but its a beauriful plant and....I see questions in the future so I'm going to go with the concensus "Atlantic Pigeonwings", which also seems like it works visually.
PS I am not the kind of guy who will bury you in links and flack every cool website I see, but there's just something about this one: Memorial Ecosystems