Medical Definition of Apocynum
: a genus of chiefly American perennial herbs of the dogbane family (Apocynaceae) with opposite leaves and small white or pink flowers comprising the dogbanes of which several (especially A. androsaemifolium and A. cannabium) are the source of substances with physiological activity resembling digitalis—see indian hemp 1
Seen and Heard
What made you want to look up Apocynum? Please tell us where you read or heard it (including the quote, if possible).