Calla lily family (4)
I believe the answer is:
arum
'calla lily family' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for arum that I've seen before include "A sort of lily." , "genus of plants" , "Plant of the family Araceae, eg lords-and-ladies" , "A spirit for a lily" , "plant with a white spathe" .)