Valeriana officinalis

Valeriana officinalis, known as valerian, was a medicinal herb, present on Earth and, possibly, other planets.

The Fifth Doctor recognised its presence (in particular, of Valeriana officinalis centiculare europea) in a tonic he was given from the pharmacist Mergrave in the fictional Castrovalva. (TV: Castrovalva)

In the 1820s, in Killingworth, Peri Brown suggested the administration of valerian to some victims of the Rani, pointing it out on a botanic 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)