knob celery vs turnip-rooted celery

knob celery and turnip-rooted celery both are nouns.

Word	Noun	Adjective	Verb	Adverb
knob celery	Yes	No	No	No
turnip-rooted celery	Yes	No	No	No

As nouns, knob celery and turnip-rooted celery are synonyms defined as:

knob celery and turnip-rooted celery: grown for its thickened edible aromatic root

Other synonyms of knob celery include Apium graveolens rapaceum, celeriac, celery root, root celery.

knob celery (noun)	turnip-rooted celery (noun)
grown for its thickened edible aromatic root	grown for its thickened edible aromatic root