The king of all flowers, at least on our prairie, is the gray-headed coneflower. I particularly like it when they’re just pushing their petals out, before they fall like skirts below them.
I used the Tallgrass Prairie Wildflowers field guide by Doug Ladd through the Nature Conservancy for most of the IDs. The link is to the second edition… the one we have is no longer available I think. It’s really difficult to identify flowers by photo… this one was pretty good, though!
In addition I took photos of the lead plant, purple-headed coneflower, blue vervain, asters, white prairie clover and purple prairie clover, wild bergamot, black-eyed Susans, water hemlock, germander, milkweed, butterfly milkweed bush, prairie coreopsis, golden coreopsis, goldenrod, prairie coneflower, and several things I can’t remember at the moment… but which I’ll name as I fall asleep.