The larger, in general, of the two kinds of spores produced after meiosis in the life cycle of a heterosporous plant, and on germination giving rise to the female gametophyte (embryo sac). [source: APweb:Glossary]
Comment
If you are annotating to this structure for Zea mays or other grasses, please also add an annotation to the corresponding floret type. Choose the most specific term possible from: spikelet floret (PO:0009082), ear floret (PO:0006354), upper floret of pedicellate spikelet of ear (PO:0006350), upper floret of sessile spikelet of ear (PO:0006352).