Yarrow

Yarrow was a medicinal herb used by Gaius to treat Morgana's mysterious illness (A Remedy to Cure All Ills).

Appearances

 * A Remedy to Cure All Ills

Trivia
Yarrow is a prolific herb, considered invasive in some circumstances; it is used in herbal medicine to treat nosebleeds and stop bleeding, and an infusion of the herb is used to lower fever.