living plants

A asked a man at the pet store for a real plant to put in my Betta Fish Tank. He suggested this weird looking one and im hoping its one that is compatible with my fishie. I really don`t want him to become sick...and I`ve seen him try to swim through it and got scared he might get stuck ): :cry...

Just as the title suggests, I'm looking for great ideas on what kinda of plants I should be getting for my tank to not only look great, but the kind of plants that server such great functions such as provide a cleaner habbitat for my precious companions. Let me know! Sorry for any mistakes in...