Iris verna vs vernal iris

Iris verna and vernal iris both are nouns.

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

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

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

Other synonyms of Iris verna include dwarf iris.

Iris verna (noun)	vernal iris (noun)
low-growing spring-flowering American iris with bright blue-lilac flowers	low-growing spring-flowering American iris with bright blue-lilac flowers