swan-flower vs orchid

swan-flower and orchid both are nouns.

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

As nouns, orchid is a hypernym of swan-flower; that is, orchid is a word with a broader meaning than swan-flower:

swan-flower: any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan
orchid: any of numerous plants of the orchid family usually having flowers of unusual shapes and beautiful colors

Other hypernyms of swan-flower include orchidaceous plant.

swan-flower (noun)	orchid (noun)
any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan	any of numerous plants of the orchid family usually having flowers of unusual shapes and beautiful colors