If you mean the three rows in the field with the bare ground to the left, they are “black oilseed” sunflowers of unknown parentage. I just picked black oilseeds out of a birdseed mix; made sure they would germinate, and then planted them.
Sunflowers are pretty promiscuous, and will cross breed freely, so there’s a lot of variation in what came up. Those large ones on the end do have black seeds, but a few of the larger ones in that stand have grey-striped seeds. Some of the plants have multiple flower heads clustered on the top of the stem; and a few have several flower heads on separate short stems, etc. They are about 4’ tall.
The other large sunflowers with the row of flowers & garden fence to their left are from purchased “Large Grey Stripe” sunflower seeds; and they are (almost) all true to type. They are approaching 8 feet tall.
We’re borderline Zones 5 & 4, in extreme SW South Dakota. South Dakota is one of the premiere states for commercial sunflowers, which is why I decided to try them this year.
As to your other posted question, I don’t have the discipline required to write a book.
I’ll answer separately about the walking onions later, though basically we are using them (first year to harvest any) like regular onions.