The sansevieria  picked up the name mother in laws tongue from the sharpness of the evergreen sword like leaves that grow in an upward fashion.While all plants purify air-borne toxins the snake plant is among the top plant's tested and added to a list by NASA (National Aeronautics and Space Administration) for removing, benzene, formaldehyde and other harmful toxins. Its very low maintenance requiring plant, thriving to light and shady places, thats why became a green queen of corporate spaces.