I thought you could only patent something if you modified it genetically? That's how Monsanto does it. You can't patent a "natural" plant.
And as a schedule 1 I thought you couldn't research it? So how could you patent it?
You cannot patent a seed variety BUT...
Plants & seed varieties CAN be protected via PVPA for a period of 20 years. After those 20 years are up, I think anybody can do pretty much whatever they want with that particular protected variety.
Speculation of this point is pretty much useless since all the needed info is readily available by looking around a little.
Pretty sure this link to Cornell U. will answer any questions one might have concerning PVPA (Plant Variety Protection Act of 1970)
https://www.law.cornell.edu/uscode/text/7/chapter-57
As to your last comment quoted...
The powers that be can & do exactly as they please.
They believe the saying "Sometimes it's easier to ask for forgiveness than permission. Lol