Birr

Birr was the home planet of the Verdant. It had been visited by the Doctor at some point in its history, where he had met the Verdant leader Phlege. On his second visit to the planet, he discovered that a Rostrow space mission led by Lahk had arrived to gather plant specimens, unaware that they were taking intelligent beings prisoner, and in return the Verdants were preventing the Rostrow ship from leaving. The Doctor, with the assistance of Duh, helped to make peace between the two peoples. (DWA: Mission for Duh)