Allium ascalonicum vs onion

Allium ascalonicum and onion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Allium ascalonicum	Yes	No	No	No
onion	Yes	No	No	No

As nouns, onion is a hypernym of Allium ascalonicum; that is, onion is a word with a broader meaning than Allium ascalonicum:

Allium ascalonicum: type of onion plant producing small clustered mild-flavored bulbs used as seasoning
onion: bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb

Other hypernyms of Allium ascalonicum include Allium cepa, onion plant.

Allium ascalonicum (noun)	onion (noun)
type of onion plant producing small clustered mild-flavored bulbs used as seasoning	an aromatic flavorful vegetable
	bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb
	the bulb of an onion plant