dwarf iris vs Iris verna

dwarf iris and Iris verna both are nouns.

Word	Noun	Adjective	Verb	Adverb
dwarf iris	Yes	No	No	No
Iris verna	Yes	No	No	No

As nouns, dwarf iris and Iris verna are synonyms defined as:

dwarf iris and Iris verna: low-growing spring-flowering American iris with bright blue-lilac flowers

Other synonyms of dwarf iris include vernal iris.

dwarf iris (noun)	Iris verna (noun)
low-growing spring-flowering American iris with bright blue-lilac flowers	low-growing spring-flowering American iris with bright blue-lilac flowers
low-growing summer-flowering iris of northeastern United States