swan orchid vs swan-flower

swan orchid and swan-flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
swan orchid	Yes	No	No	No
swan-flower	Yes	No	No	No

As nouns, swan orchid and swan-flower are synonyms defined as:

swan orchid and swan-flower: any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan

Other synonyms of swan orchid include swan-neck, swanflower, swanneck.

swan orchid (noun)	swan-flower (noun)
any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan	any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan