Well we call the entire Ipomoea genus "morning glories." Its just a language thing, sweet potatoes are in the same genus. Whatever you call it the genus Ipomoea has many members with active alkaloids
This abstract says its not closely related to the batatas (sweet potatoes) complex. Which I would take to mean it has a better probability of containing interesting alkaloids. I don't see any references to batatas containing lysergicamides, and i would suspect that there would be even more interest in growing sweet potatoes if there were.
mmm sweet potatoes