Flower Gloria cultivated in Maryland (8)
I believe the answer is:
marigold
'flower' is the definition.
(marigold is a kind of flower)
'gloria cultivated in maryland' is the wordplay.
'cultivated' indicates anagramming the letters.
'in' indicates putting letters inside.
'maryland' becomes 'MD' (abbreviation).
'gloria' with letters rearranged gives 'arigol'.
'arigol' going into 'md' is 'MARIGOLD'.
(Other definitions for marigold that I've seen before include "Garden plant of the daisy family" , "Orange daisy" , "Flower - grim load (anag)" , "Yellow or orange flower" , "The flower has a gold rim, oddly" .)