Flowering plant groups of sheep or birds picked up (5)
I believe the answer is:
phlox
'flowering plant' is the definition.
(I've seen this before)
'groups of sheep or birds picked up' is the wordplay.
'groups of sheep or birds' becomes 'flocks'.
'picked up' indicates a 'sounds like' (homophone) clue.
'flocks' is a homophone of 'PHLOX'.
(Other definitions for phlox that I've seen before include "Plant with clusters of white, red or purple flowers" , "Garden plant with clustered flowers" , "Plant bearing flowers" , "Bloomer" , "Scented border plant" .)