# Opium poppy (Papaver somniferum)

**Papaver*; Greek *mēkōn*; the juice, *opion**

**Known today as.** *Papaver somniferum*; opium is the dried latex of its unripe seed heads.

Kind: Plant  
Qualities: Cold and dry in the fourth degree (Galen): the extreme of cold among the simples.  
Poisoning: Opioid poisoning (https://thethinkingpress.org/materia-medica/poisons/opioid)  
Toxic: yes

> **Caution.** Addictive; overdose stops the breath.

## What does modern science say?

The source of morphine and codeine, among the most important medicines ever found, and of the whole crisis of opioid addiction.

## Pharmacognosy and toxicology

- **morphine**: about a tenth of raw opium
- **codeine**: 
- **thebaine**: the starting point of oxycodone
- **papaverine**: a smooth-muscle relaxant
- **noscapine**: an antitussive

**Mechanism.** Morphine acts at the -opioid receptors of the brain and gut: analgesia, euphoria, constipation, and the slowing of breath.

**Dose.** About 200 mg of morphine by mouth in the unaccustomed; far more in the tolerant.

**Standing.** Morphine and codeine are on the WHO list of essential medicines; opium tincture is a controlled drug.

## What lore surrounds it?

The poppy belonged to Hypnos and Morpheus, sleep and dreams; some have seen Homer’s nepenthe in it (see [Nepenthe](https://thethinkingpress.org/materia-medica/nepenthe)).

The red poppy of Flanders Fields and Remembrance Day is the corn poppy, *Papaver rhoeas*, a different species from Canale’s opium poppy, *Papaver somniferum*, and it carries none of its narcotic latex. The two are often run together, but the symbol of remembrance belongs to the field weed, not to the source of opium.

## What did the older authorities say?

**Dioscorides.** Describes cutting the unripe heads to gather the tears of juice, and warns that too much brings a sleep from which there is no waking.

**Paracelsus.** Gave the name *laudanum* to a potent remedy he carried; the tincture of opium in wine later took the name.

**Thomas Sydenham.** The seventeenth-century English physician praised opium as the most universal and effective of the remedies God had given for suffering.

## Sources

- Dioscorides, *De materia medica*.
- Galen, *On the Powers of Simple Medicines*.
- Goldfrank’s *Toxicologic Emergencies*, 11th ed. (2019).

---

*Opium poppy.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-09-25. The Thinking Press. https://thethinkingpress.org/materia-medica/opium-poppy

Historical description, not medical advice.