Irish potato vs starches

Irish potato and starches both are nouns.

Word	Noun	Adjective	Verb	Adverb
Irish potato	Yes	No	No	No
starches	Yes	No	No	No

As nouns, starches is a hypernym of Irish potato; that is, starches is a word with a broader meaning than Irish potato:

Irish potato: an edible tuber native to South America; a staple food of Ireland
starches: foodstuff rich in natural starch (especially potatoes, rice, bread)

Other hypernyms of Irish potato include solanaceous vegetable, root vegetable.

Irish potato (noun)	starches (noun)
an edible tuber native to South America; a staple food of Ireland	foodstuff rich in natural starch (especially potatoes, rice, bread)