Which plant is the source of the powerful opioid painkiller morphine?

The opium poppy is the plant source of morphine, a powerful opioid painkiller. Its scientific name is Papaver somniferum. Morphine is concentrated in the opium poppy’s milky latex, which flows from the seed capsules when unripe pods are shallowly scored and then dried.

Opium contains several alkaloids, but morphine is its principal analgesic compound. The dried latex has historically been used for pain relief, while purified morphine became a more precise medical drug. German pharmacist Friedrich Sertürner isolated morphine from opium in the early 19th century and named it after Morpheus, the Greek god of dreams.

The plant also produces codeine and thebaine. These compounds are chemically related but have different medical roles; thebaine is especially important as a starting material for manufacturing several semisynthetic opioids. Morphine works mainly by activating mu-opioid receptors in the brain and spinal cord, reducing the perception of pain.

A common mix-up is confusing the opium poppy with the decorative California poppy or with coca, which is associated with cocaine. Morphine is medically valuable but can cause tolerance, dependence, respiratory depression, and fatal overdose, so its use is tightly controlled.