Tangerines are a form of citrus fruit. The seeds form this fruit are similar in structure to other citrus seeds. Citrus seeds are called simple fruit seeds. Each seed forms from a single ovary and can be fleshy or dry when mature. Dry seeds include various beans and seeds, including sunflower seeds. Fleshy seeds result in fruits like peaches, tomatoes, cucumbers and citrus.
Tangerine seeds are wet and slippery when fresh. The surface is irregular and can have grooves in skin that is loose. The seed has a rounded base with a sharp tip. It is white. The surface, or skin, of the seed can sometimes tear, exposing the inner structures of the seed. As the seed dries out, the skin becomes thin and leathery and can become prone to tears. The surface of the seed protects the growth components from damage. It also helps to keep the inner portion moist until the seed germinates.
Tangerine seeds are endicots. The term endicot refers to the seeds single embryo and single mass of stored food. The other structures of the tangerine seed sit under the seed coat and are protected by the seed coat. Tangerine seeds are only viable for a short time when fresh. As the seed coat dries out, the food store dries out and limits the viability of the seed. Tangerine seeds are a simple seed type. This simplicity and the ease of identifying the structures with the naked eye make it a seed that can be used in biology classes to teach seed anatomy.
Tangerine seeds, like other citrus seeds, are best planted when fresh. As the skin dries out, it hardens. As it hardens, it begins to allow the food store to become dry, reducing nutrition available to the embryo. If the embryo dries out, the seed will not sprout. This process of aging and drying out reduces the viability of tangerine seeds over time. The viability of the seed is highest as soon as the seed is removed from the fruit. Washing the seed thoroughly can help to remove sugars that could result in bacterial issues with the seedling. As time passes, the seed becomes naturally less viable.