Endosperm is a tissue found in the seeds of flowering plants, specifically in the angiosperms. It serves as a food reserve for the developing embryo, providing essential nutrients during germination. The endosperm is typically rich in starch, proteins, and oils, which support the growth of the new plant. During seed development, the endosperm forms from the fertilization of the central cell in the ovule. It can be classified into three types: nuclear, cellular, and haploid endosperm, each differing in structure and function. The endosperm plays a crucial role in the life cycle of plants, ensuring successful seedling establishment.