fever tree

definition: African tree supposed to mark healthful regions
example:
speech part: noun
synonyms:
definition: tall fast-growing timber tree with leaves containing a medicinal oil
example:
speech part: noun
synonyms: blue gum
definition: 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
example:
speech part: noun
synonyms: bitter-bark
definition: any of several trees having leaves or bark used to allay fever or thought to indicate regions free of fever
example:
speech part: noun
synonyms:

How fever tree is being used?