Sansevieria Asparagaceae Nolinoideae

Sansevieria is a historically recognized genus of flowering plants, native to Africa, notably Madagascar, and southern Asia, now included in the genus Dracaena, placed in the family Asparagaceae, subfamily Nolinoideae.

There is great variation within the species; they range from succulent desert plants such as Dracaena pinguicula to thinner leafed tropical plants such as Dracaena trifasciata. Plants often form dense clumps from a spreading rhizome or stolons. The leaves of Sansevieria species are typically arranged in a rosette around the growing point, although some species are distichous.

Sansevieria are usually small in pots, and their variance is too broad to be accurately described in a single article - you just have to see all the different varieties that are available!

According to a NASA Clean Air Study, Dracaena trifasciata is capable of purifying air by removing some pollutants such as formaldehyde, xylene, and toluene. Sansevierias absorbs carbon dioxide at night, although oxygen is released during daylight. Nighttime absorption of CO2 purportedly makes them especially suitable bedroom plants. 

According to feng shui, because the leaves of sansevierias grow upwards, the plants can be used for feng shui purposes. They are recommend placing pots near the toilet tank to counter the drain-down vibrations.

Since the leaves are potentially poisonous if ingested, they are not  recommended for exposure to children or pets.