columbo vs American columbo

columbo and American columbo both are nouns.

Word	Noun	Adjective	Verb	Adverb
columbo	Yes	No	No	No
American columbo	Yes	No	No	No

As nouns, columbo and American columbo are synonyms defined as:

columbo and American columbo: any of various tall perennial herbs constituting the genus Frasera; widely distributed in warm dry upland areas of California, Oregon, and Washington

Other synonyms of columbo include American gentian, deer's-ear, deer's-ears, pyramid plant.

columbo (noun)	American columbo (noun)
any of various tall perennial herbs constituting the genus Frasera; widely distributed in warm dry upland areas of California, Oregon, and Washington	any of various tall perennial herbs constituting the genus Frasera; widely distributed in warm dry upland areas of California, Oregon, and Washington