I received it as T. ankersii, but many of the photos don't look like the same plant. There does seem to be a fair amount of variation, so possibly the one I have is just a different form. It does have the same growing habit though.
For years I would look for different species whenever a shipment of T. javanicum would come into the local petshops. Nothing different ever popped up though
Sad that they still sell it for aquariums, when they really don't grow underwater. Glad that you got some for your vivs. Are you having success growing them?