Wild Cherry Bark or Black Cherry (Prunus serotina) has long been known and used for combating cough and respiratory irritations, bronchitis, pneumonia, fevers and inflammation of the respiratory system itself. The inner bark (cambium) has been used in the form of syrup, tea, tincture, capsule and even a plaster over the chest in medicinal applications.
The main warning on the Wild Cherry Bark is the fact that the entire tree, except for the flesh of the cherries themselves, contain prunasin, a cyanide type of glycoside that converts to hydrocyanic acid when digested. Hydrocyanic acid (some of you may recall my explanation and dialog in Shadow Scorpion concerning HCN) is highly toxic! The Wild Cherry contains the highest levels of prunasin in the autumn after the sunlight begins to fade and temperatures start to remain below 55 degrees F.
Wild Cherry Bark is best harvested in late spring when prunasin levels are lowest. It is the prunasin that makes the inner bark of the cherry trees smell like almond extract.
The interesting thing about all this is that most people do not know why the Wild Cherry Bark works as a medicine for the lungs and bronchial tubes. People know that it can sooth coughing and aliments that cause coughing fits, but why? It is because of the very toxic nature of the bark that it is medicinal to us. HCN is as I said highly toxic and can kill humans. However, in properly harvested Wild Cherry Bark, the digestion of the small amounts of prunasin converts to just enough HCN to literally create a minor and temporary paralysis of the lungs and bronchial tubes. This paralysis stops the contraction (cough) of the lungs and bronchial tubes and thus eases the coughing mechanism.
This is just one of many examples of how poisons can many times act as medicines and it all comes down to the how, when and how much.