Finally some of these showed up in my yard. They've been growing all around the neighborhood for decades but just got to my yard. Even the Brook Lobelia from half a mile away beat them here. Slackers. :D
@anniesue LOL, they also have the effrontery to be a variety that is not in any of my flower books. The online nature apps insist they are Creeping Bellflower but the flowers don't all grow on one side of the stem which is supposed to be strongly indicative. So maybe Slacker Bellflowers is what I shall name them. :)