[mækrәuspә'rændʒiәm]
n.
[植]大孢子囊

[ noun ]
a plant structure that produces megaspores
<noun.plant>

Macrosporangium \Mac`ro*spo*ran"gi*um\, n. [NL. See {Macro-},
and {Sporangium}.] (Bot.)
A sporangium or conceptacle containing only large spores; --
opposed to {microsporangium}. Both are found in the genera
{Selaginella}, {Isoctes}, and {Marsilia}, plants remotely
allied to ferns.