Yeah, that's what they said at the aquarium store where I tried to buy it.
They can't sell anacharis at all in Maine. It's also illegal to stock
non-native fish anywhere outside. They have really strict rules about this
stuff in Maine, but I didn't realize how much it would affect my pond plans.

I looked before i went to work, and after. I cant find much searching
for Maine pond club, pond society, or even koi club.