The common spider plant is such a ubiquitous feature of the domestic landscape that I have scarcely ever paid attention to it as an actual plant. They are legendarily sturdy, putting up with all sorts of abuse: under- and over-watering, cats, being left in the shade or out in the cold. You name it and a spider plant has managed to live through it. I always considered it a bit of a miracle when one of them flowered, but apparently it isn’t that big a deal.
First of all, its real name is Chlorophytum comosum and its is native to central and southern Africa, growing in generally wet habitats, particularly along stream courses. Its classification has changed repeatedly since it was first described as Anthericum comosum by Swedish naturalist Carl Peter Thunberg in 1794. It was taken out of its original genus and reassigned to its present genus in 1862 by Henri Antoine Jacques. For decades it was a member of the Anthericaceae, until in 2009 that family was dismantled in the face of molecular evidence and Chlorophytum was reassigned to the subfamily Agavoidae in the Asparagaceae (asparagus family).
The wild type has long lanceolate green leaves that have streaks of lighter green running longitudinally. The two popular cultivars are “Vittatum,” which moderately green leaves showing a broad central white stripe and yellow to white flower stems (scapes), and “Variegatum,” which has narrower white bands along the edges of the leaves and green flower stems. The latter became more popular than the former after the 1990s. All varieties have tiny white flowers that are borne in small sprays of 1-6 six-petaled blossoms. The scapes themselves can be a foot and a half long.
The plant’s habit is a basal rosette from which the leaves arch upward and then down. The flower scapes will arch above the leaves, but small plantlets appear at the ends of them, weighing them down. In its natural habitat, this is how the plant reproduces vegetatively and apparently monospecific stands of them are common. (It is regarded as invasive in parts of southeastern Australia, where the species has escaped into the wild after being thrown out with garden refuse.)
This habit makes it a popular hanging house plant. A healthy specimen has dozens of “spiderettes” hanging from the main plant. Any of them can be broken off and replanted; they grow readily in soil-based potting mix. Occasionally the leaves brown at the tips because of fluoride, which is derived from excessive perlite in the potting mix. Excessive sodium, caused by water softeners, can also burn the left tips. Final too much boron, from overfertilization, can do the same thing. The browning is caused by a build up of salts, it doesn’t harm the plant, but can be gotten rid of by using distilled water or rain water.
They tolerate a wide variety of soils, from loamy to sandy to clay and mixtures between the extremes. Spider plants do not like full sun—they are understory plants in the wild—but thrive in part-sun. They prefer to dry out between waterings. They can be grown outside in USDA Hardiness Zone 10 and have naturalized in parts of Florida and Alabama.
One interesting benefit of having spider plants in the house is that they clean the air. They are quite effective in removing benzene, xylene, and other “out gassing” chemicals from the indoor atmosphere, which is more important in really well insulated modern homes.
They are commonly called spider plants because the dangling plantlets look like small spiders hanging at the end of web thread. They are also rather mysteriously called “airplane plants,” for which I could find no explanation at all. Apparently in Puerto Rico they are called mala madre or “bad mother,” and so would not be a good gift for a Puerto Rican mother-in-law.