Spider plant (Chlorophytum comosum, (Thunb.) Jacques)

Identity

The spider plant (Chlorophytum comosum (Thunb.) Jacques, 1862) is a herbaceous perennial in the genus Chlorophytum, part of the asparagus family, Asparagaceae. Few houseplants are more widespread, and it owes that place to its toughness and how readily it multiplies. ^{1 2}

Its common name comes from the plantlets hanging at the ends of long, thin runners, like spiders dangling from their threads. In French-speaking horticulture it goes by phalangère, and in western Switzerland by herbe vaudoise. ³ The genus name Chlorophytum joins the Greek chloros, "yellow-green" or "green," with phyton, plant, a nod to the foliage, while the epithet comosum refers to the tufted, hair-like look of the rosette. ^{4 5} English speakers also call it airplane plant or ribbon plant, and German speakers know it as Grünlilie, "green lily." ⁶

Recognition

Look first at the rosette: dense, built from narrow, arching, strap-shaped leaves 20–45 cm (8–18 in) long, plain bright green or striped with white or yellow depending on the cultivar. ^{7 8} In a pot, the foliage typically stands 30–45 cm (12–18 in) tall and spreads 30–60 cm (12–24 in), more once the runners trail from a hanging basket. ^{5 9}

The runners are the giveaway. These long, slender stems carry small plantlets at their tips, already equipped with leaves and root buds. Once they touch moist potting mix, the plantlets root quickly and become new plants. ^{8 5}

Small white flowers about 1 cm (0.4 in) across open along a branched flowering stem that can grow quite long. ^{3 7} Below ground, the plant builds fleshy, tuberous roots that store water and eventually distort pots that are too tight. ⁵

Useful taxonomy

Thunberg described the species, and Jacques moved it to its current genus in 1862; the accepted name is Chlorophytum comosum (Thunb.) Jacques. ¹ Beyond the botanical name, most confusion comes from trade names and variegated cultivars. The main reference points are:

• Chlorophytum comosum (Thunb.) Jacques: accepted name
• Anthericum comosum Thunb.: historical basionym
• Chlorophytum comosum 'Vittatum': cultivar with a white central stripe
• Chlorophytum comosum 'Variegatum': cultivar with white margins

The genus Chlorophytum sits in the Asparagaceae, subfamily Agavoideae. Retail names such as "airplane plant" or "ribbon plant" do not mark separate species; the accepted scientific name is the stable reference. ^{1 2} The reference chromosome number is 2n = 28. ¹⁰

The story of its description has a literary twist. In 1827 the still-unknown plant reached the Belvedere botanical garden near Weimar; Goethe received an offshoot, wrote a description and sent it in January 1828 to the Prague botanist Kaspar Maria von Sternberg. Sternberg published the first valid name that same year, Anthericum comosum, the basionym of the species. ¹

Habitat and range

Across Africa, the native range of Chlorophytum comosum is broad. In the west it covers Sierra Leone, Liberia, Ivory Coast, Burkina Faso, Nigeria, Cameroon and Equatorial Guinea; in the east and south, Sudan, Ethiopia, Kenya, Uganda, Tanzania, Malawi, Mozambique, Zambia, Zimbabwe, Eswatini and South Africa. ^{1 1} The plant grows in the seasonally dry tropical biome, in shaded understory and in some coastal areas. ^{4 8}

Brought to Europe around the middle of the 19th century, it went on to become a houseplant worldwide. ³ Outside its home range it is almost always cultivated, but it has naturalized locally in mild climates, notably in Western Australia and Bangladesh. ⁷ In France the species is known only in cultivation, and it is listed on that basis in the national species inventory run by the Muséum national d'Histoire naturelle. ¹¹ Native African range, regions where it is simply grown and areas of introduction therefore need to be kept apart.

Life cycle and reproduction

Indoors, the plant reproduces mostly vegetatively. Plantlets form at the tips of the runners when the plant gets short days and long, uninterrupted nights, meaning less than twelve hours of light a day, for at least three weeks. ^{9 5} That photoperiod trigger explains why some plants kept under bright lamps in the evening never produce "babies."

The easiest way to propagate it is to set a plantlet on moist potting mix, where it roots within a few days, or to divide an old clump, whose fleshy roots pull apart easily. ^{8 2} Growing from seed collected from the capsules works, but it does not faithfully reproduce the variegation of the cultivars. ⁸

Heavy feeding favors foliage at the expense of runners, so a moderate dose of fertilizer is the better route to plantlets. ⁵

Uses and risks

Most spider plants are grown as ornamentals, usually in a hanging basket that shows off the trailing runners; where winters stay frost-free, the plant can also serve as a ground cover in partial shade. ² It suits beginners: very tolerant, it accepts a wide range of conditions as long as it is kept from frost and direct sun. ^{2 5}

On safety, the ASPCA lists Chlorophytum comosum as non-toxic to cats, dogs and horses. ^{12 9} That makes it one of the few houseplants worth recommending in a home with pets, often the deciding point against irritating species such as the aroids.

In its home range, the species also has a traditional use: the tuberous roots are reported to be edible, and the Nguni peoples of South Africa credit them with a mild laxative effect. ^{7 4}

The spider plant is often promoted as an air purifier since the NASA Clean Air Study, which listed it among species able to absorb certain compounds in a sealed chamber. ⁷ In real indoor conditions, the measured effect is small and debated; grow it because it is easy, not for a supposed cleaning function. ⁷

Varieties, look-alikes and related plants

The best-selling forms are variegated cultivars, not separate species. 'Vittatum' carries a broad white central stripe, while 'Variegatum' has white margins on darker green leaves; both have received the RHS Award of Garden Merit. ^{7 2} 'Bonnie' is a compact selection with curly leaves.

Before buying, check the condition of the fleshy roots, the firmness of the rosette and whether the runners are healthy. A plant bought for its plantlets may carry none if it is young or has been grown under long hours of light. Among rosette-forming houseplants, the spider plant stands apart through its arching, strap-shaped leaves and above all its plantlet-bearing runners, which no Sansevieria or Dracaena look-alike produces. ⁹

Main sources

• Plants of the World Online / Kew, Chlorophytum comosum (Thunb.) Jacques
• Royal Horticultural Society, Chlorophytum comosum, spider plant
• Missouri Botanical Garden Plant Finder, Chlorophytum comosum
• NC State Extension, Chlorophytum comosum
• University of Wisconsin Horticulture Extension, Spider Plant, Chlorophytum comosum
• ASPCA, Spider Plant (Chlorophytum comosum) non-toxic entry
• Wikipedia (FR), Chlorophytum comosum
• Wikipedia (EN), Chlorophytum comosum
• SANBI PlantZAfrica, Chlorophytum comosum
• Encyclopaedia Britannica, spider plant
• INPN / French National Museum of Natural History, Chlorophytum comosum
• Tropicos / Missouri Botanical Garden, Chlorophytum comosum chromosome counts