One of the two layers of tissue that usually cover the ovule, contiguous to the inner integument and usually involved in forming the micropyle at the apex. [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).