I don't think there can be a definite answer here. That tank could have been planted with healthy thriving plants the same week the picture was taken. It's a beautiful tank, even with no information from the the person who designed it. I purchased hornwort this year that was grown outside and it's just as bushy and green, I have given some away to a friend for her indoor aquarium. If you look online at pond plants for sale you can find some.