fern seed vs fern

fern seed and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
fern seed	Yes	No	No	No
fern	Yes	No	No	No

fern seed (noun)	fern (noun)
the asexual spore of ferns that resembles dust; once thought to be seeds and to make the possessor invisible	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores