family Palmae vs palm tree

family Palmae and palm tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Palmae	Yes	No	No	No
palm tree	Yes	No	No	No

family Palmae (noun)	palm tree (noun)
chiefly tropical trees and shrubs and vines usually having a tall columnar trunk bearing a crown of very large leaves; coextensive with the order Palmales	any plant of the family Palmae having an unbranched trunk crowned by large pinnate or palmate leaves