Feverfew root
Feverfew root (originally Padekia) is a special kind of medicinal herb in Dragon Quest IV. It is the only known medicine capable of healing a fever. The castle town of Parthenia is dedicated to farming this herb, but their stock has run down to nothing. The last remaining herbs are in a nearby cave, but are guarded by demons, to the dismay of the inhabitants.
When Alena and her party visit the southeastern continent, Kiryl falls ill with fever. Alena gathers a small group of mercenaries to try and recover the Padekia, but fails. Luckily, the Hero and his party is able to recover the plant and rid Kiryl of his ailment.