[5] The leaves have fine hairs, are green at the bottom and shade to purplish at the top; they are 2–4 centimetres (3⁄4–1+1⁄2 in) long and broad, with a 1–2 cm petiole (leaf stalk), and wavy to serrated margins.

[4] Though superficially similar to species of Urtica (true nettles) in appearance, L. purpureum is not related to them, the genus Lamium belonging to the mint family, not the nettle family, the "dead" in the name "dead-nettle" referring to the inability of Lamium species to sting.

[11] Lamium purpureum is native to Europe and Asia[citation needed] but it can also be found in North America.

It is a common weed in the western and eastern United States,[12] Canada, Ireland, and the British Isles.

[citation needed] The pollen is crimson red in colour and thus very noticeable on the heads of the bees that visit its flowers.

The charm in question (dating, according to scholarly consensus, probably from the late ninth century) calls for the three herbs involved (the other two being feverfew and plantain) to be heated in butter to prepare an ointment, which is then rubbed on the site of the pain with the blade of a knife, while the lengthy charm is recited by the folk practitioner, who thereby aligns herself (or himself) with the patient – in contradistinction to the evil supernatural beings believed to have caused the pain with their magical arrows.