I would research whatever it is you have and make 110% sure it's not poisonous - green leaves or not. A plant like Diffenbachia has nice green leaves....but if your cat eats it, it'd unfortunately poison them. There's a list of some toxic plants on here: http://www.thecatsite.com/forums/sho...d.php?t=174854
The Cat Fancier's Association also has a list on their site:http://www.cfainc.org/articles/plants.html
Most of my houseplants are poisonous to cats (I have snake plants, a pothos, an aloe, etc). I was going to put them all in my bedroom when I got Harley if she showed any interest in them. Thankfully, she isn't interested in any of my plants whatsoever. She's given them all a thorough sniff and decided that they don't smell good.