Yellow Jessamine: A Species of Gelsemium That’s a Very Toxic Plant

What native flowering vine is perfumed, profuse, and in bloom in early spring just when we need floral encouragement the most? It’s yellow jessamine, or Carolina jasmine—Gelsemium sempervirens. (Its species name—“always living”—refers to Gelsemium’s glossy, evergreen foliage.) This is a cascading, fast-growing vine that makes a spectacular bower over doorways, softening hard fence edges, and stopping passersby, even in their preoccupied, city tracks. It is also one of the most toxic plants on the planet.

But don’t panic. Unless you’re a Russian whistleblower.

Photography by Marie Viljoen.

Growing natively from Guatemala through Virginia, yellow jessamine’s first stop in the US is Texas, where it is often the first flower to bloom in the new year. It is widely distributed in the Southern US but also in the nursery trade, which has spread it beyond its natural range. It shows remarkable cold hardiness for a plant also at home in Central America. (There are three Gelsemium species: the others are G. rankinii, native to Southeastern US, and which has no scent; and G. elegans, native to East and Southeast Asia.)

While European honeybees are drawn to the nectar-rich flowers of Gelsemium, especially if there is no other food source, the nectar in high doses may be toxic to them. At least, this is the chatter in concerned bee-keeping circles, but it is hard to find a study that confirms this—because there is no such study. Still, with ancient, anecdotal stories circulating via cut-and-paste (and cemented into truth by an entry on Wikipedia with a cul-de-sac of a citation), they are hard to dismiss completely.

But what about native pollinators and yellow jessamine?

Yellow jessamine might actively benefit native bumble bees: A 2010 study concluded that “gelsemine, a nectar alkaloid found in Gelsemium sempervirens, lessens the severity of gut pathogen infections in bumble bees.” Self-medicating bees. I have seen fat carpenter bees besieging yellow jessamine, and “robbing” the flowers by puncturing the base of their nectaries from the outside, to suck out sweetness, leaving less food for the slimmer Eastern bumble bees that enter politely from the flower’s mouth.

Gelsemium Toxicity

The toxic alkaloids in all Gelsemium species include gelsemine, but dozens of other alkaloids have been isolated from the genus, which has been studied extensively, pharmacologically. For humans and other animals, all Gelsemiums are harmful (and may be lethal) if ingested in very high, very unlikely doses. These could be self-administered deliberately. Sometime in the second half of the 18th century, the author Sir Arthur Conan Doyle purposefully overdosed on Gelsemium in order to observe its effects in different quantities. He documented his findings and submitted them to the British Medical Journal in 1879.

The poison may also be ingested via foul play: In 2012, after he died unexpectedly in Surrey, at the age of 44, an autopsy report showed that Russian whistleblower Aleksander Perepilicchnyy had traces of Gelsemium elegans in his stomach.