water flaxseed vs great duckweed

water flaxseed and great duckweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
water flaxseed	Yes	No	No	No
great duckweed	Yes	No	No	No

As nouns, water flaxseed and great duckweed are synonyms defined as:

water flaxseed and great duckweed: cosmopolitan except South America and New Zealand and some oceanic islands

Other synonyms of water flaxseed include Spirodela polyrrhiza.

water flaxseed (noun)	great duckweed (noun)
cosmopolitan except South America and New Zealand and some oceanic islands	cosmopolitan except South America and New Zealand and some oceanic islands