If you look at my set up (a few posts down) the plants in it are real. They are called air plants because they do not need any soil. You can glue them anywhere you want. That way you don't have to worry about pesticides, bug infestations (not pretty, I had one with a live plant), and other unwanted stuff. Also you only have to soak them at the most once a week. This way they do not increase the humidity level in your enclosure, which could cause viral infections... The only thing is they are hard to find, mainly because if they were not in my set up they wouldn't look very nice. They don't grow much bigger than the ones in my picture, so they won't take over your set-up.
If you deside to go with other plants here are some things to think about, if you haven't already
You don't want to increase the humidity.
You need a plant that is not toxic.
Make sure it has not been treated with any sort of pesticide.
You will also need a uv light for live plants.
Here is an awsome website for vivarium set-ups, they have some info on plants that can go in terrariums as well. You just need to find plants that don't need much humidity.
http://www.blackjungle.com/home.htm
Hope this helped,
Lisa
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0.1 Hypo Leopard Gecko
0.1 Albino Leopard Gecko
0.1 Blizzard Leopard Gecko
1.0 Pacman Frog (Phatty)
1.0 Lovebird (Tony Montana)
1.0 Elkhound (Otto)
0.1 Malamute (Paris)
5.0 Bettas