The small, hard object at the center of a cherry is often called a pit, but its botanical identity is more complex than a simple seed. While the pit itself is not the seed, it is a protective shell that contains the seed, making the cherry a reproductive unit of the tree. Understanding this distinction involves exploring the fruit’s structure, which also reveals why the pit carries a chemical compound and how it must be treated to successfully grow a new tree.
Defining the Cherry Pit: Anatomy of a Drupe
The cherry is scientifically classified as a drupe, a type of fleshy fruit characterized by a single, hardened inner layer that surrounds the seed. This category includes other “stone fruits” like peaches, plums, and apricots. A drupe is composed of three distinct layers, all derived from the flower’s ovary wall.
The outermost layer is the exocarp, the thin, shiny skin of the cherry. Beneath that lies the mesocarp, the thick, sweet, and edible flesh that people consume. The final and innermost layer is the endocarp, the rigid, woody shell commonly referred to as the pit or stone.
The pit’s primary function is protection, acting as a biological safe for the embryo inside, shielding it from damage and premature germination. This protective endocarp is composed of sclereids, specialized cells that create a dense, lignified matrix, giving the pit its characteristic hardness. The entire structure—exocarp, mesocarp, and endocarp—develops from the mature ovary, classifying the cherry as a simple fruit.
The Hidden Danger: Amygdalin and Toxicity
The seed contained within the hard cherry pit carries a naturally occurring chemical defense mechanism known as amygdalin. This compound belongs to a class of chemicals called cyanogenic glycosides, which are stored within the seed tissue. Amygdalin itself is not toxic, but it becomes dangerous when broken down.
If the pit is crushed, chewed, or ground, the amygdalin interacts with specific enzymes in the body, initiating a chemical reaction. This process converts the compound into hydrogen cyanide, a highly poisonous substance. Cyanide is a cellular toxin that interferes with the body’s ability to use oxygen, which can rapidly damage organs.
The risk of toxicity is directly related to the dose and whether the pit’s protective shell is breached. Swallowing a few whole pits is generally not a concern because the intact, hard endocarp prevents the release of amygdalin, and the pit simply passes through the digestive system. However, chewing several pits can be dangerous, especially for children or small pets who are more susceptible to the effects of the toxin due to their lower body weight. Symptoms of mild cyanide poisoning can include headache, dizziness, nausea, and vomiting, while severe cases can lead to seizures, loss of consciousness, and respiratory failure.
Planting the Pit: Requirements for Successful Germination
To grow a cherry tree from a pit, the seed inside must first be tricked into believing it has survived a winter, a process called cold stratification. In nature, the pit falls to the ground and remains dormant through the cold, moist conditions of winter. This process breaks down chemical inhibitors within the seed, signaling to the embryo that spring is approaching and it is safe to begin growth.
Home gardeners must simulate these conditions by placing the cleaned pits in a cold, moist environment for an extended period. The pits should be mixed with a damp medium like peat moss or sand and placed in a sealed container. This container is then stored in a refrigerator, typically at a temperature between 35 and 40 degrees Fahrenheit.
The required stratification period usually lasts for about 10 to 12 weeks, though some varieties may need up to 16 weeks. This cold, damp environment softens the pit’s hard shell and breaks the seed’s internal dormancy. After this chilling period, the seeds are ready to be planted in soil to germinate and begin growing into a new cherry tree.