Abstract: The ovary is twicarpellm, twilocular with two ovules each loculus. The ovuleis unitegmic, tenuinucellar, and anatropous. The embryo sacoriginates from thesingle-archesporial. Usually the chalazal megaspore is the functional one. Thedevelopment of embryo sac is of the Polygoum type. The polar nuclei fuse beforefertilization, and antipodals are ephemeral.

Key words: Fraxinus mandshurica, Megasporogenesis, Female gametophyte