OK, Stone... I think you hit it!
Not the daisy, but the Chenopodium.
By the way, these were not purchased seed. They were received as part of my incoming seed from the large Hog Wild Swap seed-trading event this past winter, so not commercial seed.
I Googled "Chenopodium seed", then used a 15x jeweler's loupe to compare with my seed. Not only did it appear to be a match, I learned what I was calling a rough-surfaced seed was actually a tiny, shiny black seed covered by a thin seed coat. I took a small pinch of my seed and rubbed hard between my thumb and forefinger and checked again. Sure enough, there they were, the tiny, shiny black seed!
Thanks so much for your help!
Now I can do a focused search as the plants develop to narrow down as to species.
Thanks again!