American gentian vs columbo

American gentian and columbo both are nouns.

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

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

American gentian and 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 American gentian include American columbo, deer's-ear, deer's-ears, pyramid plant.

American gentian (noun)	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