pink shower tree vs horse cassia

pink shower tree and horse cassia both are nouns.

Word	Noun	Adjective	Verb	Adverb
pink shower tree	Yes	No	No	No
horse cassia	Yes	No	No	No

As nouns, pink shower tree and horse cassia are synonyms defined as:

pink shower tree and horse cassia: tropical American semi-evergreen tree having erect racemes of pink or rose-colored flowers; used as an ornamental

Other synonyms of pink shower tree include Cassia grandis, pink shower.

pink shower tree (noun)	horse cassia (noun)
tropical American semi-evergreen tree having erect racemes of pink or rose-colored flowers; used as an ornamental	tropical American semi-evergreen tree having erect racemes of pink or rose-colored flowers; used as an ornamental
	East Indian tree having long pods containing a black cathartic pulp used as a horse medicine