Allium cepa vs alliaceous plant

Allium cepa and alliaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
Allium cepa	Yes	No	No	No
alliaceous plant	Yes	No	No	No

As nouns, alliaceous plant is a hypernym of Allium cepa; that is, alliaceous plant is a word with a broader meaning than Allium cepa:

Allium cepa: bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb
alliaceous plant: bulbous plants having a characteristic pungent onion odor

Allium cepa (noun)	alliaceous plant (noun)
bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb	bulbous plants having a characteristic pungent onion odor