Robert pulled up mature aromatic herb (6)
I believe the answer is:
borage
'aromatic herb' is the definition.
(type of herb)
'robert pulled up mature' is the wordplay.
'robert' becomes 'rob' (short for Robert).
'pulled up' says the letters should be written in reverse.
'mature' becomes 'age' (synonyms).
'rob' reversed gives 'bor'.
'bor'+'age'='BORAGE'
(Other definitions for borage that I've seen before include "Bag ore for the plant" , "Blue-flowered plant with hairy leaves" , "Aromatic herb" , "Herbaceous plant with bright blue flowers" , "Blue-flowered herb" .)