Les herbes aromatique (herbs) and les épices (spices) play as fundamental a role in French cuisine as elsewhere.
In the old days, any vegetable that grew above ground was called a herbe, while anything that grew below ground was a racine or a légume-racine. Herbes à soupe, used for flavourings, would include things like radish leaves, carrot tops, celery leaves, etc.
Herbes potagères are common garden greens used as vegetables, salads or flavourings: blette, épinards, pourpier, arroche des jardins and oseille.
Les pluches are the green and tender sprigs of celery, dill, fennel, chervil, parsley etc, crying out to be snipped (ciselé) with a pair of scissors, to garnish a soup, raw vegetables or a sauce instead of being cooked in a pot.
Image by Blue moon in her eyes, Creative Commons License