Wolffiella gladiata vs duckweed

Wolffiella gladiata and duckweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
Wolffiella gladiata	Yes	No	No	No
duckweed	Yes	No	No	No

As nouns, duckweed is a hypernym of Wolffiella gladiata; that is, duckweed is a word with a broader meaning than Wolffiella gladiata:

Wolffiella gladiata: having narrow flat sickle-shaped submerged fronds; North America
duckweed: any small or minute aquatic plant of the family Lemnaceae that float on or near the surface of shallow ponds

Wolffiella gladiata (noun)	duckweed (noun)
having narrow flat sickle-shaped submerged fronds; North America	any small or minute aquatic plant of the family Lemnaceae that float on or near the surface of shallow ponds