Twelve-year-old Ted lives in a dismal plastic city where no one misses urban greenery. Except for a girl, with whom Ted falls in love and for whom he sets off in search of the rare Truffula tree. He meets Lorax, an odd forest warden before confronting with a greedy magnate who supplies the city with oxygen and has no interest in increasing vegetation, which would permit the return of chlorophyll photosynthesis.