cassia-bark tree vs cassia bark

cassia-bark tree and cassia bark both are nouns.

Word	Noun	Adjective	Verb	Adverb
cassia-bark tree	Yes	No	No	No
cassia bark	Yes	No	No	No

cassia-bark tree (noun)	cassia bark (noun)
Chinese tree with aromatic bark; yields a less desirable cinnamon than Ceylon cinnamon	aromatic bark of the cassia-bark tree; less desirable as a spice than Ceylon cinnamon bark