fen orchis vs fen orchid

fen orchis and fen orchid both are nouns.

Word	Noun	Adjective	Verb	Adverb
fen orchis	Yes	No	No	No
fen orchid	Yes	No	No	No

As nouns, fen orchis and fen orchid are synonyms defined as:

fen orchis and fen orchid: small terrestrial orchid of eastern North America and Europe having two nearly basal leaves and dull yellow-green racemose flowers

Other synonyms of fen orchis include Liparis loeselii.

fen orchis (noun)	fen orchid (noun)
small terrestrial orchid of eastern North America and Europe having two nearly basal leaves and dull yellow-green racemose flowers	small terrestrial orchid of eastern North America and Europe having two nearly basal leaves and dull yellow-green racemose flowers