Keimlingsblätter

Keimlingsblätter, also known as cotyledons, are the first leaves to emerge from a germinating seed. They are a crucial part of the embryonic development of a plant, providing the initial nourishment for the seedling until true leaves develop and can photosynthesize.

There are two main types of cotyledons: epigeal and hypogeal. In epigeal germination, the cotyledons emerge above ground, often turning green and performing photosynthesis for a short period. This is common in plants like beans and sunflowers. In hypogeal germination, the cotyledons remain below the soil surface and primarily function as a food source, transferring stored reserves from the seed to the developing shoot. Examples of plants with hypogeal germination include peas and oaks.

The structure and number of cotyledons are key characteristics used in plant classification. Monocotyledonous plants, such as grasses and lilies, have a single cotyledon. Dicotyledonous plants, like roses and maples, have two cotyledons. These embryonic leaves can vary in size and shape, and in some species, they wither and fall off shortly after the emergence of the true leaves. Their presence and behavior are fundamental to a plant's early survival and growth.