Viper bowstring hemp

When I paused to take photos of this common garden ornamental, I was struck by how appropriate its common name snake plant is. Unfortunately, too many different plants are called by that name, so I could call it by its binomial, Dracaena trifasciata, or call it the viper bowstring hemp. This name comes from the fact that the fibers of this plant were used to make bowstrings by the Yoruba people who live in the native range of the plant: from the Congo westwards to Nigeria. There are so many varieties of this plant (another one in the photo below) that it is sometimes hard to believe that they are all in the same species. At least one study has tried to make sure that several plants that we lump into this species are indeed one.

Although the center of diversity of the 120 species of the genus Dracaena lies in west Africa, there is increasing evidence that the genus evolved in sub-tropical Asia. The main clue to this strange event is that the closest cousins of these species are found in tropical and sub-tropical regions of eastern Asia. They have gone extinct in that part of the world, but the oldest species of Dracaena seem to lie in Hawaii and parts of South America. This apparently also happened to the family of plants called the Begoniaceae (the Begonias). So there is the beginning of a mystery here: how did that first dispersal happen, and then a second dispersal to Africa. I’m on tenterhooks now, waiting for the solution.

The plant is easy to grow indoors, and we once had one which grew very well even away from direct sunlight. I find that different varieties as well as closely related species are being sold as “natural air purifiers”. This is not entirely wrong, since many papers have been written about its ability to slowly soak up volatile organic molecules like benzene and formaldehyde. Good ventilation is perhaps a more effective way of getting rid of those indoor air contaminants. There is no evidence that the plant gets rid of suspended particulate matter, which is a major component of air pollution in India.