corn lily vs iridaceous plant

corn lily and iridaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
corn lily	Yes	No	No	No
iridaceous plant	Yes	No	No	No

As nouns, iridaceous plant is a hypernym of corn lily; that is, iridaceous plant is a word with a broader meaning than corn lily:

corn lily: any of several South African plants of the genus Ixia having grasslike leaves and clusters of showy variously colored lily-like flowers; widely cultivated
iridaceous plant: any bulbous plant of the family Iridaceae

corn lily (noun)	iridaceous plant (noun)
any of several South African plants of the genus Ixia having grasslike leaves and clusters of showy variously colored lily-like flowers; widely cultivated	any bulbous plant of the family Iridaceae