What are cotyledons?

Cotyledons are the first embryonic leaves or seed leaves that appear in the germinating seed of a flowering plant (angiosperm). They are an essential part of the seed and play a crucial role in the early stages of a plant's life. Cotyledons can vary in number and structure depending on the type of plant.

There are two main types of cotyledons:

Monocotyledons (Monocots): Plants belonging to the monocot group have only one cotyledon. Examples of monocots include grasses, lilies, orchids, and palms. Monocot cotyledons are usually thin and narrow.

Dicotyledons (Dicots): Plants in the dicot group have two cotyledons. Examples of dicots include most trees, shrubs, vegetables, and many flowering plants. Dicot cotyledons can have various shapes, including thin and elongated or thick and fleshy.

The cotyledons' primary function is to provide nourishment to the developing embryo in the early stages of germination. They contain stored nutrients, such as carbohydrates, proteins, and lipids, which the growing seedling uses until it can produce its own energy through photosynthesis. As the seedling grows, the cotyledons may either wither and die, as in many dicots, or remain functional, as in some monocots, depending on the plant species. Ultimately, the cotyledons give way to the true leaves, which take over the role of photosynthesis and further growth in the plant's life cycle.