I’ve always assumed the spider plant (Chlorophytum comosum) got its name from its hanging stems, ones that drip down like so many spider legs. Or possible from its rosette of arching leaves. Aren’t they vaguely spideresque? Or maybe because of its numerous somewhat spidery babies?
However, it turns out the plant’s appearance has nothing to do with its name.
Here’s what happened.
A Long, Long Time Ago, In Europe
There is a European plant called Anthericum liliago that was widely believed to be an antidote to spider bites. This belief is a very ancient one found throughout the Mediterranean region, including Greece, Spain, Italy and France. In these countries, this plant is commonly called something that would translate as spider plant, for example, hierba contra la araña or hierba de la araña (Spanish), phalangère (Phalangium is a type of a type of spider), herbe à l’araignée or plante-araignée (French), etc.
As far as I can see, there is no association between A. liliago and spider bites in the English-speaking world. Instead, the plant usually goes under the common name St. Bernard’s lily. (No, I don’t know where that name comes from!)
Out of Africa
When Chlorophytum comosum, native to the forests of South and West Africa, was first formally described by the Swedish naturalist Carl Peter Thunberg in 1794, he called it Anthericum comosum, considering it a close relative of St. Bernard’s lily (A liliago), southern Europe’s “spider plant”. And indeed, other than St. Bernard’s lily being a more upright grower, the two have a lot in common, including grasslike leaves and nearly identical small white flowers.
Both plants were later moved to a new genus, Phalangium (which, if you recall, is the name of a spider) by French botanists, again because of the believed spider-bite antidote status of what was now Phalangium liliago, thus reinforcing the belief.
By the time our plant was moved to its current placement in Chlorophytum in 1862 (the St. Bernard lily was late put back into the genus Anthericum), Chlorophytum comosum was already being called spider plant (or the regional equivalent of the same) and that name has stuck ever since.
By the way, the name Chlorophytum has nothing to do with spiders: it simply means “green plant”.
So, your spider plant got its name from the supposed spider-bite cure properties of a close relative.
That said, I suggest you not try and apply spider plant juice on the wound the next time you are bitten by a venomous spider, but rather that you see a doctor!