being native to six of the ten World Geographical Scheme for Recording Plant Distributions regions of Africa (West Tropical Africa, West-Central Tropical Africa, Northeast Tropical Africa, East Tropical Africa, South Tropical Africa, and Southern Africa). Cultivation Chlorophytum comosum is a popular houseplant. The species with all-green leaves forms only a small proportion of plants sold. More common are two variegated cultivars: C. comosum 'Vittatum' has mid-green leaves with a broad central white stripe. It is often sold in hanging baskets to display the plantlets. The long stems are white. There is also a "curly" version with this type of striping and compact size. C. comosum 'Variegatum' has darker green leaves with white margins. It is generally smaller than the previous cultivar. The long stems are green. Both cultivars have gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017). Propagation Propagating Chlorophytum comosum commonly occurs through potting the plantlets, informally referred to as 'spiderettes', or 'pups', directly into potting soil attached to the main plant or cutting the running stems and then potting them. Spider plants are easy to grow, being able to thrive in a wide range of conditions. They will tolerate temperatures down to , but grow best at temperatures between and . Plants can be damaged by high fluoride or boron levels. Spider plants are non-toxic to humans and pets, and are considered edible. Air purification The NASA Clean Air Study suggested that air plants were effective at removing common household air toxins formaldehyde and xylene; however, these results are not applicable to typical buildings, where outdoor-to-indoor air exchange already removes VOCs at a rate that could only be matched by the placement of 10–1000 plants/m of a building's floor space. The results also failed to replicate in future studies, with a 2014 review stating that: In the laboratory settings uses in the Clean Air Study, spider plants were shown to reduce formaldehyde pollution, and approximately 70 plants would neutralize the formaldehyde released by materials in a representative (ca. ) energy-efficient house, assuming each plant occupies a pot. See also List of air-filtering plants References External links Agavoideae Flora of West Tropical Africa Flora of West-Central Tropical Africa Flora of Northeast Tropical Africa Flora of East Tropical Africa Flora of South Tropical Africa Flora of Southern Africa Garden plants of Africa House plants Plants described in 1794 Taxa named by Carl Peter Thunberg Low light plants