Embryogenic cultures of longleaf pine (Pinus palustris Mill.) were established from female gametophytes with intact zygotic embryos (at developmental stages 1 and 2) cultured on MSG and DCR basal media in darkness. Induction of embryogenic tissue was observed from explants cultured on both basal media containing glucose, or maltose or sucrose as carbon source. All four levels of each carbon source (15-90 g/L) used supported production of embryogenic tissue. Both auxin (2,4dichlorophenoxy acetic acid(2,4-D) and cytokinin (N6-benzyladenine (BA) at 2 and 1 mg/L; 3 and 0.5 mg/L, 5 and 2.5 mg/L and 2,4-D alone at lOmg/L were effective in producing embryogenic tissue. Maintenance and proliferation of embryogenic tissue was achieved by transferring extruded emoryogenic tissue to half-strength modified MSG medium supplemented with casein hydrolyaate (lg/L). The level of 2,4-D was reduced to 0.5 mg/L and BA was eliminated from the medium. This transfer resulted in active proliferation of embryogenic tissue, and cultures were scaled up to 700 tissue masses each weighing approximately 250 mg. These emoryogenic tissue masses have been subcultured 23 times to date for a period of 8 months. Embryogenic tissue examined microscopically both at 3 or 4 weeks and 8 months after initiation revealed somatic embryos at several early stages of development. Somatic embryos from tissues on initiation medium were morphologically different from those on maintenance or proliferation medium. All somatic embryos were pre-cotyledonary and resembled their zygotic embryo counterparts at early stages of development.