Valeriana officinalis, known as valerian, was a medicinal herb, present on Earth.
The Fifth Doctor recognised its presence in a tonic (along with Sanicula europaea and rosemary) he was given from the pharmacist Mergrave in the fictional Castrovalva. (TV: Castrovalva [+]Christopher H. Bidmead, Doctor Who season 19 (BBC1, 1982).)
In Killingworth in the 19th century, Peri Brown suggested the administration of valerian to some victims of the First Rani, pointing it out on a botany book of Ravensworth, self-declared amateur botanist. He confirmed it was Valeriana officinalis, an indigenous plant which could be found nearby; he sent her to harvest it. She collected some leaves in Redfern Dell. (TV: The Mark of the Rani [+]Pip & Jane Baker, Doctor Who season 22 (BBC1, 1985).)