Daffodils were a form of flower found on Earth.
Constance and Henry Clarke had wilting daffodils at their wedding due to it being wartime. (AUDIO: The Behemoth)
The Master and the Autons once used Auto-jets disguised as plastic daffodils in an attempt to take over the Earth. (TV: Terror of the Autons)
The Twelfth Doctor once defeated a broadsword-wielding Bors using a daffodil. (TV: The Magician's Apprentice)