The Amazing Nightshade Family
Hardly a day passes that we don’t learn something new and interesting about our friends in the plant kingdom. To me, one of the most fascinating families of plants is the nightshade family, or Solanaceae. It includes the potato, tomato, eggplant, tobacco, and the peppers (except ground black peppercorns; a separate family). This family contains some of the deadliest toxins known, as well as compounds we’ve synthesized for medicine, and yet we have daily contact with many of them. Keep in mind that plants cannot uproot themselves to flee from the dangers of insects, disease, or herbivores, so for their defenses they evolved and perfected chemical weapons. Why don’t we meet the family, while at the same time learning a little organic chemistry.
Potato, Solanum sp. — They were first domesticated in Peru and Bolivia, between 8000 and 5000 B.C. They contain a glycoalkaloid called solanine, that can be mildly toxic. If the potato is green under the skin it shows a concentration of the chemical, so don’t eat it. Green areas just below the peel should be removed, too. Potatoes are the #1 vegetable fresh market crop, taking up twice the total acreage of sweet corn. Being half Irish, they are by far my vegetable of choice.
Tomato, Solanum sp. — The earliest origins go back to the Aztecs, c. 700 A.D. In the early 16th Century they were introduced to Europe. Among the wealthy they were considered poisonous, but the poor loved them. That’s because wealthy people used flatware made from pewter, an alloy of tin and lead. The acid in the tomato would eat through the pewter, and lead would leach out. The French thought they had aphrodisiacal properties, hence the name pomme d’amour, love apple. Another reason they were thought poisonous is their resemblance to another family member, the Wolf Peach, Lycopersicon. The Old German word for tomato was Wolfpfirsich, the name derived from old folk tales that werewolves could be called up using members of this family.
Tomatoes are a crucial ingredient of pizza, thought to be invented in Naples, Italy, in the late 19th century. Because Italy was only recently a united country (1881), the restaurateur wanted to reflect the colors of the new flag, so the green, white, and red became basil, mozzarella, and tomato sauce. Are they a vegetable or fruit? Although the Supreme Court ruled in 1893 they are a vegetable (for tax purposes), the definition of a fruit is the edible fleshy body surrounding a seed or seeds, and that’s good enough for me. Actually those fleshy parts you’re eating are the plant’s ovaries. Yum!
Tobacco, Nicotiana sp. — N. Tabacum was and is cultivated for tobacco, and like our first two entries, also from the New World. Drop for drop, nicotine is more deadly than both strychnine and Western Diamondback rattlesnake venom, and three times more lethal than arsenic. Another deadly toxin the plant produces is anabasine, better known as neonicotine. Today, neonicotinoids are the #1 selling pesticide in the world, and the prime suspect in crashing the bee population. That’s why they’re banned in Europe. Recent studies have shown more positive uses for nicotine. It stimulates the brain’s production of dopamine, a neurotransmitter. For decades, a different chemical was used for that purpose — levadopa, also called L-dopa, used to treat Parkinson’s, but a side effect was involuntary muscle movements. Nicotine doesn’t have that side effect. In fact, it’s showing promise in treating not only Parkinson’s, but also Tourette’s syndrome and schizophrenia. It’s normally administered in the form of chewing gum or a transdermal patch.
Deadly Nightshade, Atropa belladonna — Also known as Devil’s berries, naughty man’s cherries, or beautiful death. The Genus name gives it away as a main source of atropine, a deadly poison. It was the plant of choice for assassins in the Middle Ages. Women back then used the herb’s oil to dilate their pupils, in order to look more seductive. That’s what the doctor puts in your eyes prior to an eye examination. The plant also contains scopolamine, another toxic alkaloid. Cattle, horses, sheep, goats, and rabbits are immune to the berries, but pets are not. The plant was used by the ancients for an anaesthetic for surgery, due to its effects of dizziness or drowsiness. Scopolamine (or hyoscine) is used to treat motion sickness. In the alley behind my house is Solanum dulcamara, or Bittersweet Nightshade. Whereas the belladonna flowers are purplish brown and bell-shaped, these are purple with yellow stamens, and very attractive. They eventually form red berries. I’m not worried about any animal getting sick, because these guys have another defense: they’re well guarded by a thicket of blackberry thorns.
As a side note, when I was in the Army infantry, part of our combat training gear was an atropine injector. It’s an antidote for nerve agents, like the Sarin gas recently used in Syria. It was about the size of a Magic Marker. If attacked by nerve gas, you were supposed to push the plunger with your thumb as you jammed it down into your thigh muscle. I’m really glad I never got the chance to use it.
Eggplant, Solanum melongena — Also known as augergine (fr. Catalan alberginia), garden egg, or mad apple, due to a legend that it causes insanity. Why, that’s crazy! The first written record is from China, 544 A.D. It’s been known to be allergenic, especially to those hypersensitive to allergies, but cooking usually neutralizes the threat. I know people love it, but I’ve never cared for the spongy texture. To be fair, though, I once tasted my date’s Moussaka at a Greek restaurant, and I must admit it was pretty good.
Datura sp. — D. stramonium, is known as Jimsonweed, Angels’ trumpets, Devil’s snare, and Voodoo cucumber. It also contains atropine and scopolamine and is highly hallucinogenic. In his book The Serpent and the Rainbow, Wade Davis tells how Voodoo priests used it to create real “zombies.” A related species is the Borrachero tree of Colombia, also known as Angels’ trumpets. It has also been used to make a chemical, burundanga, which can disorient victims, blocking their ability to form memories or make free will choices, similar to date rape drugs. Again, ancients used it for anaesthesia during surgery or bone setting.
Mandrake, Mandragora officinarum — Because it contains deliriant hallucinogenic tropane alkaloids, and the shape of the root often resembles the human form, it is steeped in all kinds of supernatural lore. Legend has it that it would scream when pulled, and instantly kill the puller, so it was often tied to an animal to pull out. Effects of ingestion are similar to atropine poisoning; blurred vision, dizziness, pupil dilation, vomiting, and rapid heart rate (tachycardia). In proper dosage it, too, was used for anaesthesia, but also used to treat melancholy, rheumatic pains, and convulsions. Larger doses can lead to delirium and madness.
Peppers, Capsicum sp. — Their defense system consists of capsaicin, the “heat” in a pepper. For some reason, birds seem to be unaffected. Widely grown in warmer climates, I don’t think I need to tell you all their culinary uses. I’m not a pepper guy, I don’t like hot foods, but I do make chicken paprikash, flavor a stew with just a touch of organic roasted cayenne, and use a 4oz. can of Ortega diced green chilis in my lentil chili. Scoville heat units, or SHU, are how the heat in peppers is rated. I don’t include “chili (or chile) peppers” in this list, as it can apply to so many varieties.
Bell pepper 0
Pimento and paprika (usually) 100 – 1000
Poblano 1000 – 2000
Jalapeno 2500 – 10,000
Cayenne 30,000 – 50,000
Habanero 100,000 – 350,000
Ghost pepper, Carolina Reaper, Komodo Dragon 1,000,000 – 2,200,000
Let’s compare these numbers to pepper spray, used for self-defense (I hope). The retail pepper spray you’re likely to find at the gun shop is about 2,000,000 SHU, roughly that of the Ghost pepper. Military or police grade pepper sprays can be as mush as 5,000,000 SHU. They are literally chemical weapons. What does the UN have to say about that? The UN Conventions on Chemical Weapons, in 1992, banned the use of chemical agents, including tear gas, pepper spray, and of course nerve agents — but only for use on the battlefield. Oddly, the Convention doesn’t include domestic police use. However, the UN Commission on Human Rights does, and over the years the U.S. has received many visits from UN inspectors.
If you’ve been as impressed by this marvelous family of plants, consider that they’ve got a well over 100 million years head start over us. That’s a long time in which to evolve the kind of complex and sophisticated systems. Plants really are amazing beings.