yellow iris vs Iris pseudacorus

yellow iris and Iris pseudacorus both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow iris	Yes	No	No	No
Iris pseudacorus	Yes	No	No	No

As nouns, yellow iris and Iris pseudacorus are synonyms defined as:

yellow iris and Iris pseudacorus: common yellow-flowered iris of Europe and North Africa, naturalized in United States and often cultivated

Other synonyms of yellow iris include yellow flag, yellow water flag.

yellow iris (noun)	Iris pseudacorus (noun)
common yellow-flowered iris of Europe and North Africa, naturalized in United States and often cultivated	common yellow-flowered iris of Europe and North Africa, naturalized in United States and often cultivated