I have a backyard. It’s no palatial green lawn and there are, regrettably, no topiaries. (Note to self: inquire with roommates about purchasing some topiaries.) But it’s my own little green space in the midst of this concrete jungle.
About a week ago, some brightly colored berries growing in one corner of the yard caught my eye. The small, multicolored berries were attached to a vine growing some pretty funny looking leaves. When I cut one of the berries open, it looked and sort of smelled like a tiny, tiny tomato. Naturally, I had to know what they were, so I tupperwared ‘em and brought ‘em to work.
I really was going to write about something besides poison this time, but the universe had other ideas.
Those berries and funny-shaped leaves are the hallmark of Solanum dulcamara, or bittersweet nightshade, a climbing vine originally from Eurasia. It was invited to the US to be a pretty face in the crowd, but now it’s classified as a noxious weed or invasive species in at least 35 states. Like a lot of non-native species it has the very unpleasant habit of running amok, smothering native species, and being downright impervious to attempts to eradicate it.
As far as structure goes, bittersweet nightshade has what you might call a ‘devil may care’ attitude. Its berries don’t ripen all at once, so immature green berries, semi-mature orange berries, and fully mature red berries all hang out together and even rub elbows (seeds?) with the small purple flowers that will eventually turn into berries.
The leaves too seem to have decided to throw regularity to the wind and are a mix of shapes and sizes. Smaller leaves are more or less arrowhead shaped, while large ones are more heart shaped. Most, but not all, of the larger leaves have a set of double, irregular-shaped lobes on their bases. Bittersweet nightshade does its own thing, ok?
For those of you who are unfamiliar with the nightshade family, technically known as the Solanaceae (so-lan-AY-see-ee) family, it’s full of charmingly poisonous plants like henbane, mandrake, jimsonweed, and belladonna (also known by the oh-so-creative name of deadly nightshade). Before you go rushing the exits, you should know that, depending on who’s counting, there are between 2,000 and 4,000 plants in the Solanaceae family and not all of them are terrifying; some are probably in your pantry or your backyard right now: tomato, eggplant, tobacco, potato, husk apple, chili pepper, sweet (or capsicum) pepper, petunias….they’re all nightshades.
The Solanaceae are a well travelled, highly influential family to say the least. There are mandrakes carved on the side of an ivory casket of Tutankhamun. There’s archaeological evidence that capsicum peppers were being eaten 9,000 years ago in Peru. There are frescoes of eggplants in Roman villas and pre-Columbian potato-shaped ceramic vessels from the Americas. Both King Hamlet of Shakespearean fame and Ulysses of Greek fame ran into henbane: it worked out somewhat more favorably for Ulysses who just had to deal with his crew being transformed into pigs. King Hamlet, meanwhile, had to deal with being dead and haunting his son. (A father’s work is never done.) There are larger historical echoes as well. The Irish Potato Famine, anyone? The transatlantic tobacco trade?
Bittersweet nightshade has led a quiet life in comparison to many of its relatives. It is poisonous, but you, as a normal-sized human, would have to eat an awful lot of it to do anything other than sour your stomach. Its poison, like most poison in nature, isn’t about us. It’s about repelling insects and browsing animals, so just get over yourself.
Like a lot of nightshades, bittersweet nightshade contains a toxin called solanine. Also like a lot of nightshades, the poison isn’t concentrated in just one place; it’s in the berries, it’s in the leaves, the stems, the roots...everywhere. Nightshades, let me reiterate, are not fucking around.
Chances are actually pretty good that you’ve ingested some solanine in the past day or two. It’s in peppers, tomatoes, and potatoes (to name a few), though its concentration in those foods is much, much too low to have an impact on the average person.
In higher concentrations than a dish of salsa, pizza, or poutine, solanine is trouble. It has a really neat, but really nasty ability to shut down the effects of a certain neurotransmitter called acetylcholine (a-see-till-KO-leen). Solanine blocks a chemical whose normal function is to break down acetylcholine, letting the neuron know it’s time to stop firing.
Think of the neuron like a light switch—acetylcholine flips the light switch on, the other chemical flips it off. Except, when solanine gets involved the light switch just stays on and soon the bulb burns out, the neuron dies. Then, like those strings of christmas lights where one burnt out bulb causes all the others to go out, the other neurons nearby start shutting off too.
Solanine is part of a class of molecules called alkaloids, nifty nitrogen-containing compounds made primarily by plants. They might not be about us, per se, but they do have some very pronounced effects on us and our nervous systems. Morphine was the first identified alkaloid, but that’s not all. Cocaine, caffeine, nicotine, strychnine, and quinine are all alkaloids. Do you have sudafed in your medicine cabinet? Take a close look at it’s active ingredient: pseudoephedrine! A certified alkaloid derived from an Asian plant called Ephedra sinica.
I still haven’t decided if I’m going to try to remove the bittersweet nightshade plant in my backyard. Yes, it’s weedy, non-native, and slightly poisonous. But it’s beautiful and it’s given me a great excuse to stop and examine every leaf, vine, and berry I come across. Now when I’m late to happy hour it isn’t because I decided to change my entire outfit at the last minute, it’s because I was crawling around someone’s front garden to see if that green berry is a sibling to ones in my backyard. My friends, as you might imagine, are very patient people.