Ulmus americana vs white elm

Ulmus americana and white elm both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ulmus americana	Yes	No	No	No
white elm	Yes	No	No	No

As nouns, Ulmus americana and white elm are synonyms defined as:

Ulmus americana and white elm: large ornamental tree with graceful gradually spreading branches common in eastern North America

Other synonyms of Ulmus americana include American elm, rock elm, water elm.

Ulmus americana (noun)	white elm (noun)
large ornamental tree with graceful gradually spreading branches common in eastern North America	large ornamental tree with graceful gradually spreading branches common in eastern North America