A Bit of Prairie Or My Shirt?

It’s definitely blue and it’s definitely flax, but is it (Wild Blue, Lewis, Prairie) Flax ( Linum lewisii, Linum perenne, Linum perenne lewisii are all synonyms) native to the other side of the Mississippi? Or is it Linum usitatissimum, native to Eurasia and the Middle East and for thousands of years cultivated as a source of fiber and seed oil.
According to this site, the way to tell L. usitatissimum is that “the sepals of Cultivated Flax have acutely pointed tips; the inner sepals also have ciliate margins.” But of course I didn’t know that in the field.Here’s another one: a Delphinium, but not a native species.