1) Macrosporangium 2) Sporangium 3) Spore case 4) Spore sac 1) Macrosporangium 
the sporangium containing megaspores. cf. microsporangium
(from the article `plant`) ...sporophyte produces sporangia, which bear sporocytes (meiocytes) that undergo meiosis to form spores. Microsporangia (male sporangia) produce ... ...as megaspores and the smaller as microspores. The megaspores develop into female gametophytes and the microspores into male gametophytes. ... ...within whic...
The spore producing body, producing megaspores.
macrosporangium noun a plant structure that produces megaspores