n.大孢子叶...

megasporophyll的音标：megasporophyll的英式发音音标为：[ˌmegə'spɔ:rəfɪl]megasporophyll的美式发音音标为：[ˌmegə'spɒrəˌfɪl]...

It has evolved by fusion of the two edges of the megasporophyll.心皮是由大孢子叶两边愈合进化而来的....