Cherry Plum Trees & Air Toxicity

Leaves and the Air

• The cherry plum is native to Central Asia and the Balkans. It is hardy in United States Department of Agriculture zones 5B to 8A. The tree provides brilliant color much of the year with deciduous purple leaves that also provide fall color changes. The tree has simple, slightly serrated thin leaves. Cherry plum is not toxic to the air but, as with all trees, its respiration can help to cleanse the air of toxins. The release of oxygen from the leaves is a natural byproduct of photosynthesis that enriches the air.

Toxicity Source

• The source of the toxins in the Prunus group are the leaves and fruits. Because the cherry plum produces few if any fruits, the leaves are the dangerous portion of the plant. They contain cyanogenic glycoside. These are also called cyanogens and are toxic when ingested. Damaged or drying leaves are the most toxic and build up high levels of cyanide. This occurs when they are eaten and the animal breaks the leaf tissue by chewing. The leaves are most toxic then because the vacuoles inside the leaves that store the toxins are damaged and the cyanide spreads.

Air Exposure

• The toxicity of the leaves increases slightly as they are damaged, but it lessens over time. Initial exposure to air increases the cyanide levels in the leaves, but as they dry the cyanogenic effects decrease because of the evaporation of the volatile oils. For this reason, leaves that have fallen to the ground during early fall could have the highest levels of toxicity, which become more benign as they dry. The potential for animal ingestion is the highest in unsupervised pastures, so dropped leaves should be removed from grazing animals' reach.

Cyanide Toxic Factors

• The genus Prunus has several toxic properties. The cyanogenic glucosides are amygdalin, prunasin and prulaurasin. These toxins turn into hydrogen cyanide during a chemical process that involves the introduction of air and the separation of water molecules. The hydrogen cyanide lends its characteristic bitter flavor to some stone fruits. Crushing intensifies the flavor and in many cases renders the fruit inedible to humans because of the taste. Birds seem to find no fault with such fruits and readily consume them and then spread the seed in their excrement. They suffer no ill effects from eating even fruits with very high levels of hydrogen cyanide.