Endosperm is food laden tissue which provide nutrients to the growing embryo . It develop from triple fusion in the angiosperms and in gymnosperm the female gametophyte is endosperm.
In angiosperms based on the division of primary endosperm nucleus , the endosperm is of three types—- Nuclear, cellular, and helobial
NUCLEAR ENDOSPERM :In this type free mitotic nuclear division takes place in the primary endosperm nucleus without the formation of walls. The big central vacuole pushes the nuclei towards periphery after nuclear division cell wall form around each nuclei and a cellular structure form covering the whole space .This is the most common endosperm type. Ex. Coconut
HELOBIAL ENDOSPERM: In this the primary endosperm nuclei moves towards chalazal end where first nuclear division takes place followed by transverse wall formation resulting a large micropylar cell which first divide by free nuclear division then wall formation same as in nuclear endospem & a small chalazal cell which act as haustorium.It is common in monocots.
CELLULAR ENDOSPERM: In this type each nuclear division is followed by cell wall formation. Ex Petunia
