Hemlock

Hemlock was a plant with poison-tipped thorns.

In 12th century England, hemlock was used in certain quantities as a medicine for pain relief. (AUDIO: Abbey of Heretics)

Its modification was used as ammunition in Grave Diggers weapons. (PROSE: The Secret in Vault 13)

Calidora committed suicide using hemlock. (COMIC: The Chains of Olympus)