A Field Briefing

PLANTS
ARE
POISON

A presentation by Eric Muehlstein
"Plants do not want
to be eaten."
— a thesis
400M
years of chemical warfare
since plants colonized land
The Premise

They can't run.

So they evolved an arsenal of toxins, irritants, hallucinogens, anticoagulants, cardiac inhibitors, and neurotoxic alkaloids. Every salad is a survivor's plate from a war you didn't know you were in.

Part One

Things in
your kitchen.

SPECIMEN 01
Threat: High
Potato
Solanum tuberosum
Family: Solanaceae · Nightshade
Active toxin
solanine + chaconine
The eyes and green skin are nightshade alkaloids — the same family as deadly nightshade and belladonna. Solanine disrupts cell membranes and inhibits acetylcholinesterase. Symptoms: nausea, hallucinations, paralysis, death.
FACTOne green potato can contain 80 mg of solanine. Lethal range starts around 200 mg.
SPECIMEN 02
Threat: Moderate
Apple
Malus domestica
Family: Rosaceae
Active toxin
amygdalin → hydrogen cyanide
Apple seeds. Cherry pits. Peach pits. Apricot kernels. All of them carry cyanogenic glycosides that release hydrogen cyanide when chewed and digested.
FACTThe plant put a hard shell on its delivery system — and we still call it the "fruit of knowledge."
SPECIMEN 03
Threat: High
Rhubarb
Rheum rhabarbarum
Family: Polygonaceae
Active toxin
oxalic acid
The stalks are in pies. The leaves cause kidney failure, seizures, and death.
FACTDuring WWI, the British government recommended rhubarb leaves as a vegetable. Casualties were not publicly recorded.
SPECIMEN 04
Threat: Moderate
Tomato
Solanum lycopersicum
Family: Solanaceae · Nightshade
Active toxin
tomatine + solanine
Until the 1820s, Americans believed tomatoes were poisonous. They were right about the plant. They were just eating the wrong part. The vine and unripe fruit are loaded.
FACTTomato is in the same genus as the potato — and as deadly nightshade.
SPECIMEN 05
Threat: High
Red Kidney Bean
Phaseolus vulgaris
Family: Fabaceae
Active toxin
phytohaemagglutinin
A lectin that causes violent gastroenteritis in raw or undercooked beans. As few as four or five raw beans can do it.
FACTThe plant specifically evolved to defeat slow-cooker temperatures. It engineered around your crock pot.
Part Two

Things at
the garden center.

SPECIMEN 06
Threat: Extreme
Oleander
Nerium oleander
Family: Apocynaceae
Active toxin
oleandrin · cardiac glycoside
A single leaf can kill an adult. Honey from bees that pollinate oleander is toxic. Smoke from burning the wood is toxic.
FACTIt is planted along highways across the entire American Southwest.
SPECIMEN 07
Threat: Extreme
Foxglove
Digitalis purpurea
Family: Plantaginaceae
Active toxin
digitalis · digoxin
In a controlled dose, it treats heart failure. In a slightly larger dose, it stops the heart entirely.
FACTThe therapeutic window is one of the narrowest in all of pharmacology. This is a cottage-garden assassin holding a syringe.
SPECIMEN 08
Threat: Extreme
Water Hemlock
Cicuta maculata
Family: Apiaceae · Carrot
Active toxin
cicutoxin
Looks like wild parsnip. Looks like wild carrot. Grand mal seizures within 15 minutes. "The most violently toxic plant in North America."
FACTIts cousin Conium maculatum — poison hemlock — has been killing people for 2,400 years. Including one in particular...
“Crito, we owe a cock
to Asclepius. Pay it,
and do not neglect it.”
— Socrates' last words, 399 BCE
after drinking a cup of poison hemlock
(Conium maculatum)
Part Three

And now —
the centerpiece.

6,000×
more toxic than cyanide
by weight
SPECIMEN 09 — PRIORITY
Threat: Extreme
Castor Bean
Ricinus communis
Family: Euphorbiaceae
Active toxin
RICIN
One of the most lethal natural substances known. A dose the size of a few grains of salt — about 1 mg — kills an adult human. Ricin enters cells and shuts down ribosomal protein synthesis. There is no antidote.
FACTThe plant is a popular ornamental. You can buy it at Home Depot.

Ricin's résumé.

In summary

It's not food.

Coffee is a stimulant insecticide. Capsaicin is a mammal deterrent we eat for fun. Caffeine. Nicotine. Morphine. Cocaine. Atropine. Strychnine. Every one of them is a plant trying to kill an insect, a mammal, or you.

We are opportunistic scavengers
of their failed experiments.
— end of briefing
Thank you.
Please reconsider the salad.
plantsarepoison.com
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plantsarepoison.com