mature plant embryo stage mature (stage) in Arabidopsis (related) embryo stage EM9 (related) GRO:0007177 plant_structure_development_stage GRO:0007176 A plant embryo development stage (PO:0007631) during the interval between when a plant embryo (PO:0009009) has stopped developmental growth involved in morphogenesis (GO:0060560) and one of the following: the beginning of the seed germination stage (PO:0007057) in seed plants, formation of the first vascular leaf (PO:0009025) in pteridophytes, the beginning of development of a sporangium (PO:0025094) in bryophytes, or the beginning of the formation of a plant organ (PO:0009008) such as a root (PO:0009005), shoot axis (PO:0025029), or vascular leaf (PO:0009025) in a cultured plant embryo (PO:0000010). In some seed plants, this occurs some time after the fruit ripening stage (PO:0025502) and after the dispersal of the seed (PO:0009010). This stage may be very short in plants that do not enter a plant embryo dormant stage (PO:0025377). PO_GIT:400 embryo stage EM10 (related) PO:0001081 plant embryo development stage