Megasporangium(redirected from megasporangia)
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Related to megasporangia: megasporangium
in heterosporous Pteridophyta and in seed plants, the organ in which one or several megaspores develop. Megasporangia are found singly in the axils of sporophylls (in Selaginella), on the sporophyll in a special cavity (in Isoetes), or inside sporocarps (in the order Hydropteridales). In seed plants the nucellus—the central part of the ovule—is homologous to the megasporangium.