horse cassia vs Cassia roxburghii

horse cassia and Cassia roxburghii both are nouns.

Word	Noun	Adjective	Verb	Adverb
horse cassia	Yes	No	No	No
Cassia roxburghii	Yes	No	No	No

As nouns, horse cassia and Cassia roxburghii are synonyms defined as:

horse cassia and Cassia roxburghii: East Indian tree having long pods containing a black cathartic pulp used as a horse medicine

Other synonyms of horse cassia include Cassia marginata.

horse cassia (noun)	Cassia roxburghii (noun)
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
East Indian tree having long pods containing a black cathartic pulp used as a horse medicine