Flower, one found in US state meadow (6)
I believe the answer is:
azalea
'flower' is the definition.
(I've seen this before)
'one found in us state meadow' is the wordplay.
'one' becomes 'a'.
'found in' indicates putting letters inside.
'us state' becomes 'AZ' (postal abbreviation for Arizona).
'meadow' becomes 'lea' (a lea is a grassy area).
'az'+'lea'='azlea'
'a' placed within 'azlea' is 'AZALEA'.
(Other definitions for azalea that I've seen before include "Garden plant related to rhododendrons" , "Ericaceous plant" , "Showy rhododendron-type plant" , "Plant with showy flowers" , "Rhododendron-type shrub" .)