Cortaderia selloana vs pampas grass

Cortaderia selloana and pampas grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cortaderia selloana	Yes	No	No	No
pampas grass	Yes	No	No	No

As nouns, Cortaderia selloana and pampas grass are synonyms defined as:

Cortaderia selloana and pampas grass: tall perennial grass of Pampas of South America having silvery plumes and growing in large dense clumps

Cortaderia selloana (noun)	pampas grass (noun)
tall perennial grass of Pampas of South America having silvery plumes and growing in large dense clumps	tall perennial grass of Pampas of South America having silvery plumes and growing in large dense clumps