salsify vs root vegetable

salsify and root vegetable both are nouns.

Word	Noun	Adjective	Verb	Adverb
salsify	Yes	No	No	No
root vegetable	Yes	No	No	No

As nouns, root vegetable is a hypernym of salsify; that is, root vegetable is a word with a broader meaning than salsify:

salsify (noun)	root vegetable (noun)
either of two long roots eaten cooked	any of various fleshy edible underground roots or tubers
Mediterranean biennial herb with long-stemmed heads of purple ray flowers and milky sap and long edible root; naturalized throughout United States
edible root of the salsify plant