seed A multi-tissue plant structure (PO:0025496) that develops from a plant ovule (PO:0020003) and has as parts a plant embryo (PO:0009009) enclosed in a seed coat (PO:0009088). A seed generally develops from an ovule (PO:0020003) after fertilization, but may develop without fertilization in the case of apogamy (e.g., adventitious embryos or somatic embryos). A seed is a reproductive unit of seed plants (gymnosperms, angiosperms, and fossil pteridosperms). PO:0009010 PO_GIT:405 diaspore (broad) plant_anatomy pyrene (narrow) semilla (Spanish, exact) 種子 (Japanese, exact) multi-tissue plant structure