Megasporangia

Megasporangia macrosporangium, megasporangum is produced Megaspore Cystic Reproduction organs .
Megasporangia
(1) Selaginella The megasporangium is composed of Megasporophyll The base package inside a double layer Cell wall The Epidermal cells Produced, including 4 megaspore. In the aquatic fern, is composed of a large sporangia in fruit covered with a wall Cells The formation of Sporangium Among the students, there are 32 large spores, except for one, all the other degeneration . The degradation of spores and along the wall to form a layer of tapetal cells. Cytoplasm And after become vacuolated spore wall;
(2) Seed plant In particular, Gymnosperms The ovule Because, retain and Fern The same kind of megaspore Embryo sac cells So, also called macrosporangium. In the past people used to seed plant ovule called macrosporangium, but strictly speaking, megasporangia should be the nucellus and integument and peripheral protective layer megasporangia!