Iris lacustris doesn't grow (in the wild) in Minnesota . In any event, the plant in the picture lacks crests on its sepals, which would seem to eliminate the possibility of its being a crested iris. As to the height of the inflorescence, it's difficult to judge based on the angle of the picture. I'd guess maybe a foot or so? That's certainly short for Iris versicolor, but within the range of possibility. Iris lacustris typically has a two inch maximum inflorescence height.