water orchid vs Eichhornia crassipes

water orchid and Eichhornia crassipes both are nouns.

Word	Noun	Adjective	Verb	Adverb
water orchid	Yes	No	No	No
Eichhornia crassipes	Yes	No	No	No

As nouns, water orchid and Eichhornia crassipes are synonyms defined as:

water orchid and Eichhornia crassipes: a tropical floating aquatic plant having spikes of large blue flowers; troublesome in clogging waterways especially in southern United States

Other synonyms of water orchid include Eichhornia spesiosa, water hyacinth.

water orchid (noun)	Eichhornia crassipes (noun)
a tropical floating aquatic plant having spikes of large blue flowers; troublesome in clogging waterways especially in southern United States	a tropical floating aquatic plant having spikes of large blue flowers; troublesome in clogging waterways especially in southern United States