cassia vs cassia-bark tree

cassia and cassia-bark tree both are nouns.

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

As nouns, cassia and cassia-bark tree are synonyms defined as:

cassia and cassia-bark tree: Chinese tree with aromatic bark; yields a less desirable cinnamon than Ceylon cinnamon

Other synonyms of cassia include Cinnamomum cassia.

cassia (noun)	cassia-bark tree (noun)
any of various trees or shrubs of the genus Cassia having pinnately compound leaves and usually yellow flowers followed by long seedpods	Chinese tree with aromatic bark; yields a less desirable cinnamon than Ceylon cinnamon
Chinese tree with aromatic bark; yields a less desirable cinnamon than Ceylon cinnamon