Fauna's counterpart (5)
I believe the answer is:
flora
'fauna's counterpart' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for flora that I've seen before include "Botanical specimens" , "For example, Miss Macdonald" , "Plant life of particular area" , "The plants of an area (5)" , "Plants of a region or age" .)