Company woman has mistake with plant (7)
I believe the answer is:
cowslip
'plant' is the definition.
(cowslip is a kind of plant)
'company woman has mistake' is the wordplay.
'company' becomes 'co' (abbreviation).
'woman' becomes 'W' (abbreviation eg in Woman Police Constable).
'has' means one lot of letters go next to another.
'mistake' becomes 'slip' (a slip is a blunder or mistake).
'co'+'w'+'slip'='COWSLIP'
'with' acts as a link.
(Other definitions for cowslip that I've seen before include "Yellow wild flower" , "Yellow flower for unsteady bovine?" , "Early spring flower" , "Wild flower of primrose family" , "Fictional rabbit" .)