Endosperm

The endosperm is a layer of endoskeletal tissue found in many angiosperm embryos. It surrounds the sperm inside the embryo. This layer is full of nutrients which are used to support the seed after germination. It is protected by a seed coat and the fruit, preventing it from being damaged and harming necessary resources for the embryo.

Large endosperms are typically found in monocots like corn and grain. These endosperms comprise the majority of the seed, occupying space that the embryo does not fill. While their counterpart is the cotyledon or cotyledons in other monocots and the eudicots, many plants that do not rely solely on the endosperm still depend on it during germination. The embryo may at some point absorb the endosperm; if this occurs, the embryo will store its food in a cotyledon after maturation.