Raised concern about a plant (6)
I believe the answer is:
yarrow
'plant' is the definition.
(yarrow is a kind of plant)
'raised concern about a' is the wordplay.
'raised' is a reversal indicator.
'concern' becomes 'worry' (synonyms).
'about' indicates putting letters inside.
'worry' going around 'a' is 'worray'.
'worray' backwards is 'YARROW'.
(Other definitions for yarrow that I've seen before include "Pungent plant" , "Creeping perennial plant, used in herbal medicine" , "Strong-scented creeping plant, once used in herbal medicine" , "'Achillea millefolium'" , "Wild aromatic plant" .)