Black cherry bark comes from the black cherry tree (Prunus serotina), a North American native or the choke cherry tree (Prunus virginiana L. var. demissa). (That should be easy to remember! “Choke cherry bark for cough”) It’s the inner bark, gathered in the fall that is used for herbal remedies. The tree grows wild all over North America. The bark has cyanogenic glycosides that have a powerful sedative effect on the coughing reflex.