Alstonia
noun
Al·sto·nia
| \ ȯl-ˈstō-nē-ə
\
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Medical Definition of Alstonia
: a genus of trees or shrubs (family Apocynaceae) found in tropical Asia, Australia, and Polynesia having white funnel-shaped flowers and including several (especially A. constricta) whose bark has been used medicinally for its antiperiodic and antipyretic properties (as in the treatment of malaria)