Chamomile

Hargreaves offered chamomile to the Fifth Doctor, Nyssa and Tegan Jovanka aboard the HMS Aquitaine. (AUDIO: Aquitaine)

According to a joke book which the Doctor and Yaz became trapped within, the TARDIS' tea-making machine only served English breakfast tea because the chamomile-ean circuit was broken. (PROSE: Knock! Knock! Who's There?)