Plant the French sell to queen (8)
I believe the answer is:
lavender
'plant' is the definition.
The answer is an example.
'the french sell to queen' is the wordplay.
'the french' becomes 'la'.
'sell' becomes 'vend' (vending is a kind of selling).
'to queen' becomes 'er' (abbreviation for Elizabeth Regina).
'la'+'vend'+'er'='LAVENDER'
(Other definitions for lavender that I've seen before include "Plant used in perfumery" , "Shrub with fragrant blue flowers" , "Fragrant purple flower used to scent linen etc" , "Pale bluish-purple" , "Light bluish-purple" .)