parsnip vs herbaceous plant

parsnip and herbaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
parsnip	Yes	No	No	No
herbaceous plant	Yes	No	No	No

As nouns, herbaceous plant is a hypernym of parsnip; that is, herbaceous plant is a word with a broader meaning than parsnip:

parsnip: a strong-scented plant cultivated for its edible root
herbaceous plant: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of parsnip include herb.

parsnip (noun)	herbaceous plant (noun)
whitish edible root; eaten cooked	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests
a strong-scented plant cultivated for its edible root
the whitish root of cultivated parsnip