swan-neck vs orchidaceous plant

swan-neck and orchidaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
swan-neck	Yes	No	No	No
orchidaceous plant	Yes	No	No	No

As nouns, orchidaceous plant is a hypernym of swan-neck; that is, orchidaceous plant is a word with a broader meaning than swan-neck:

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

Other hypernyms of swan-neck include orchid.

swan-neck (noun)	orchidaceous plant (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