# Hemlock (Conium maculatum)

**Cicuta*; Greek *kōneion**

**Known today as.** Poison hemlock, *Conium maculatum*, of the carrot family.

Kind: Plant  
Qualities: Cold in the fourth degree (Galenic tradition).  
Poisoning: Nicotinic poisoning (coniine, nicotine, cytisine) (https://thethinkingpress.org/materia-medica/poisons/nicotinic)  
Toxic: yes

> **Caution.** Easily mistaken for wild carrot, parsley, or fennel.

## What does modern science say?

Its alkaloid coniine paralyzes the muscles and at last the breath, while the mind stays clear, just as Plato describes. Coniine, its alkaloid, was the first alkaloid ever synthesised, by Albert Ladenburg in 1886; it blocks the junction of nerve and muscle like curare. Six to eight leaves can kill an adult, and most modern poisonings come from mistaking it for wild carrot or parsley, which it outgrows: hemlock stands head-high, smooth, spotted purple, and smells of mice when crushed.

## Pharmacognosy and toxicology

- **coniine**: the chief alkaloid; a piperidine
- **gamma-coniceine**: more toxic, highest in the young plant
- **conhydrine**: 

**Mechanism.** Coniine acts at the nicotinic receptors of nerve and muscle, first stimulating and then blocking them, as curare does.

**Dose.** About 150–300 mg of coniine, some six to eight leaves, or a few grams of the seed, has killed an adult.

**Standing.** No medicinal use. Störck’s hemlock left the pharmacopoeias in the nineteenth century.

## What lore surrounds it?

Theramenes, Phocion, and Polemarchus died by the Athenian cup as Socrates did. Its purple-blotched stem was said to carry the mark of Cain, and in Scotland the children’s name for it is “dead man’s oatmeal.”

## What did the older authorities say?

**Plato.** The *Phaedo* tells of Socrates’ death by the cup of hemlock in 399 BC, the numbness rising from his feet toward his heart.

**Athens.** Hemlock was the state poison of the Athenian courts.

**Theophrastus.** Records that Thrasyas of Mantinea devised a painless draught of hemlock juice and poppy, and that the Athenian executioners pounded the leaves and seed fresh for each dose.

**Anton von Störck.** The Viennese physician revived hemlock in 1760 as a remedy for cancers and hard swellings, testing it on himself, and for a century it stood in every pharmacopoeia as a sedative and resolvent.

## Sources

- Plato, *Phaedo*.
- Dioscorides, *De materia medica*.
- Theophrastus, *Enquiry into Plants* IX.
- Störck, A. (1760). *Libellus quo demonstratur cicutam*.
- Nelson, L. S., et al. (2007). *Handbook of Poisonous and Injurious Plants*.

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*Hemlock.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/hemlock

Historical description, not medical advice.