sporangium

A structure in which spores are formed. The sporangium may be simple and unicellular, as in the algae and fungi, or multicellular, as in the bryophytes and vascular plants. In higher plants the sporangium may be protected by a thickened outer wall. The entire protoplasmic contents may be converted into motile or nonmotile spores, which are usually liberated by rupture of the sporangium wall. See also megasporangium , microsporangium.