The garden balsam is a rare flower that grows in rocky, hard to reach places of the desert.
To complete the test of the balsam, Twinsen has to find a garden balsam and bring it to the rector of the school of magic. To get one, he must use his car, and jump from a ramp near the entrance of the cemetery, to get to an otherwise unreachable cliff. Once there he can easily pick up the flower and return. In exchange for the garden balsam, the rector gives Twinsen the horn of the blue triton.
"You must bring this flower to the Rector of the School of Magic."