The rules I am going by (I made up) are that it can go in a biotope if it grows in the area, and exotics (especially invasives) are included. After all we are learning about the environment and learning about invasive plants is a very good thing. I have already had a judge comment that he never knew "Amazon" sword plants grew in the US (And these were not exotic: E. berteroi). My goal is to fool another judge with these "American" crypts.
Also I think to be fair to many beginners starting biotopes that realistic "substitutions" should also be allowed. If you can't get American Val for an American biotope, they should be allowed to use another Val as long as they mention the substitution. I think of this biotope thing as a more educational and fun thing versus some of the highly competitive and expensive aquascaping efforts out there.
So I wouldn't worry whether its local or introduced. If its been out there growing for a while then its part of the local biotope.
Regards,
Steve Pituch
Also I think to be fair to many beginners starting biotopes that realistic "substitutions" should also be allowed. If you can't get American Val for an American biotope, they should be allowed to use another Val as long as they mention the substitution. I think of this biotope thing as a more educational and fun thing versus some of the highly competitive and expensive aquascaping efforts out there.
So I wouldn't worry whether its local or introduced. If its been out there growing for a while then its part of the local biotope.
Regards,
Steve Pituch