just to be clear, i wasn’t saying that the plant was non-native simply because it was included in the noxious weed lists of those states. i was saying that the variety found in those states was shown as non-native, as you can see here:
that said, i did some additional digging, and it does look like the particular variety noted above (C. e. leptostachyus) is likely to be native, based on a molecular analysis survey from 2015: https://academic.oup.com/aob/article/115/5/733/217532.
in other words, it looks like the USDA and FNA native/introduced maps are incorrect, and so my earlier notes are incorrect.
(it looks like the position of the word “introduced” in this text may have been the original source of the problem: https://plants.jstor.org/stable/10.5555/al.ap.flora.fna023000274. i think it should be interpreted as saying that the variety was introduced only to Europe, but because the US states are listed after, it may have been taken to suggest that the variety was also introduced to the US. and so many other references online – ex. https://www.calflora.org/app/taxon?crn=9849 – are probably also incorrect.)
so let me try to answer this again:
based on the recent molecular analysis (https://academic.oup.com/aob/article/115/5/733/217532), it looks like the C. e. leptostachyus, C. e. macrostachyus, and C. e. hermannii are native to the “New World”, and C. e. esculentus is native to the “Old World”. C. e. sativus is the cultivated variety, and it originates in the Old World. it looks like the New World / Old World split occurred many millions of years ago, probably via “nuts” that floated across the Atlantic, and it looks like the earliest members of the species would have come from Africa.
C. e. leptostachyus is what you’ll find in most of the US. C. e. hermannii and C. e. macrostachyus are found in the US mostly in the south.
C. e. esculentus and C. e. sativus have also made it to the New World. it looks like C. e. sativus is less hardy in general (and so less weedy) than its wild cousins, and it looks like the introduction of C. e. esculentus was relatively recent and so it may be too early to judge exactly what kind of impact it’ll have in the long run here. (if it does end up spreading, i think it would be fair to say it would be invasive in the conservation sense of non-native + aggressive.)
it looks like C. e. leptostachyus and C. e. macrostachyus made it to the Old World and have been causing issues there, especially since C. e. leptostachyus is more cold-hardy than the other varieties. (these New World varieties definitely are invasive in every sense over in the Old World.)