Calathea Lancifolia/ Goeppertia insignis
 
Also known as: rattlesnake plant
Family: Marantaceae
Native to: native to Brazil where it thrives in warm and moist areas of the Brazilian Rainforest
Light conditions: low to moderate light 
Watering: these plants like the soil consistently moist (but not soaking wet)
Misting: high humidity levels are a must so mist regularly. You can also increase humidity by placing a humidifier nearby or by placing a tray of water near the plant
Toxicity: NON-toxic to humans and animals
Easy to grow? yes
Air purifying: yes
 
Interesting fact: In Brazil, the Calathea lancifolia is considered to be a symbol of good luck and is often used in spiritual ceremonies.