virgin mary plants?!

I'm not sure if this has been discussed or not.. wasn't even sure how to search the forums for it. Anyways, DH and I were discussing medical patients who grow. BUT, here's the thing. If seeds are illegal to order, technically, then how exactly are you expected to be able to grow?!?! It's not like all of a sudden a plant just popped up out of the pot or ground for ya! There would've been a seed planted. Or did I miss something somewhere? Are patients allowed to order seeds from seed banks? Seeing that the post office is involved, wouldn't it make it more of a "federal" issue?? Just something I was pondering over...