The Black Cherry Tree (Prunus serotina) is the largest native cherry species in North America. This deciduous tree provides both edible fruit and powerful toxins, requiring strict caution. While the fruit is consumed by people and wildlife, consuming other parts can be dangerous. Proper identification and preparation are necessary to safely interact with this widespread species.
Identifying the Black Cherry Tree
Accurate identification of Prunus serotina is essential to prevent poisoning. The bark transitions significantly as the tree ages. Young black cherry bark appears thin, dark, and smooth, marked by horizontal lenticels, much like a birch tree.
As the tree matures, the bark darkens to a scaly, plate-like texture, often described as resembling burnt potato chips with upturned edges. The foliage consists of long, oval, glossy green leaves with finely toothed margins, typically 2 to 5 inches long.
In spring, the tree produces small, white, five-petaled flowers arranged in long, drooping clusters called racemes. Crushing a leaf or breaking a young twig releases a noticeable bitter almond-like scent. This odor is caused by the presence of cyanogenic compounds, serving as a chemical warning sign.
Edible Components: The Fruit
The fleshy pulp of the ripe fruit is the edible component of the black cherry tree. The fruit is a small, dark purple-black drupe, measuring about a quarter to three-eighths of an inch in diameter. These small cherries ripen in late summer through early fall, turning from red to a deep, dark hue.
The flavor is tart, astringent, and slightly bitter, possessing a unique wine-like complexity compared to cultivated cherries. Due to this intense flavor, the fruit is most commonly used in cooked preparations rather than eaten raw. Ripe cherries are also a food source for numerous species of birds and mammals, which helps disperse the seeds across the landscape.
Toxic Components and Safety Warnings
The danger associated with the Black Cherry Tree lies in the presence of cyanogenic glycosides, specifically amygdalin, found in almost all parts of the plant except the ripe fruit pulp. The highest concentrations of these toxins are located in the leaves, bark, stems, and the inner kernel of the fruit pit. When these parts are chewed, crushed, or digested, the glycosides are hydrolyzed by enzymes and rumen bacteria, which rapidly release highly toxic hydrogen cyanide.
The toxicity of the leaves increases dramatically when they are wilted or stressed, such as after a frost or a branch breakage, making them particularly hazardous to livestock. Cyanide acts as a potent cellular toxin, inhibiting the enzyme cytochrome oxidase and preventing the body’s tissues from utilizing oxygen. In animals, this poisoning can lead to rapid breathing, staggering, bright red mucous membranes, convulsions, and quickly result in death from anoxia.
Due to the potency of this chemical reaction, the ingestion of even relatively small quantities of wilted leaves can be lethal, particularly for grazing animals like cattle and horses. For human consumption, the primary hazard is the pit, which contains the potent cyanogenic compounds. It is imperative to understand that cracking or crushing the hard outer shell of the pit allows the toxic inner seed to be exposed, posing a serious health risk.
Safe Harvesting and Preparation
Safely utilizing black cherries requires focused attention on harvesting only the fully ripened fruit and meticulous pit removal. The cherries should be collected when they have achieved their deepest color, which indicates peak ripeness and the lowest concentration of toxins in the surrounding fruit flesh. Once harvested, the fruit must be processed to separate the edible pulp from the toxic pit before any further preparation.
The most practical method for use is to cook the fruit, which helps to mellow the tart flavor and reduces any trace bitterness. Common culinary applications include making rich jams, jellies, syrups, and sauces, and historically, the juice was used to flavor alcoholic beverages, such as rum.
When cooking, it is necessary to use a method that extracts the pulp without crushing the pits, such as a food mill or a similar device that separates the fruit from the stone. For any preparation, including simple raw consumption, every single pit must be discarded whole and undamaged. The goal is to prevent the inner seed from being broken, which would release the cyanogenic compounds into the food product.