fever tree vs acacia

fever tree and acacia both are nouns.

Word	Noun	Adjective	Verb	Adverb
fever tree	Yes	No	No	No
acacia	Yes	No	No	No

As nouns, acacia is a hypernym of fever tree; that is, acacia is a word with a broader meaning than fever tree:

fever tree (noun)	acacia (noun)
any of several trees having leaves or bark used to allay fever or thought to indicate regions free of fever	any of various spiny trees or shrubs of the genus Acacia
ornamental shrub or small tree of swampy areas in southwestern United States having large pink or white sepals and yielding Georgia bark for treating fever
tall fast-growing timber tree with leaves containing a medicinal oil; young leaves are bluish
African tree supposed to mark healthful regions