The blooms resemble Wild Sweet Potato Vine Ipomoea Pandurata.
Wild Sweet Potato is common along fence rows and field edges here.
Leaves are very different: I. pandurata are
(fiddle-shaped) vs. the dissected Merremia dissecta.
Alamo vine reached the top of the Stick House.
Flower Lady grows her Alamo Vine with Blue Pea Vine.
I found this blue pea Clitoria spp. at woods' edge in the far pasture.
I am not a real fan of vines. One bird-planted blue Morning Glory near my Camellia sasanqua last year is now a colony that must be grubbed out. I dug out huge potato-like roots of Cat Brier beside it.
Much of my gardening time is spent on vines. I read that Wisteria at a famous botanical garden requires 4 gardeners. I hack at my Wisteria all the time, and the dreaded Kudzu bugs have returned to it. I don't want them to eat all the Wisteria because their second choice for dinner is Figs when wisteria is gone.