I don't know either, KY, but as long as they make it I don't have to worry about going all the way to China to dig those roots.
I transplanted some a couple of years ago for a friend who lives in Frankfort or nearby. We found it growing on the side of a little used road and I hopped out and dug it up. Ha. We planted it in her yard and last year it was growing. Haven't asked her about it this year though.
