Stages of somatic embryogenic development. Photographs in 1A, 1F and 1G were taken on a dissecting microscope, while those in 1B through 1E depict GFP fluorescence as seen under UV illumination via confocal microscopy. A. Globular embryonic nodules (red arrows) forming along cut edges of leaf explants. B. A cluster of globular embryos on a leaf explant surface. C. An early torpedo stage embryo. D. Secondary embryo (blue arrow) emerging from a primary embryo. E. An advanced stage, bipolar embryo with cotyledonary development. F. Bipolar embryo attached to explant at base (root end). G. Advanced, bipolar embryos with leaf development and expanding hypocotyl.