Growth of cork oak somatic embryos. (A1) Initial size of a somatic embryo cultured on medium with activated charcoal (+AC), one month after embryogenesis induction. (A2) Final aspect of a somatic embryo cultured for one month on medium with activated charcoal (+AC). (B1) Initial size of a somatic embryo cultured on medium without activated charcoal (−AC), one month after embryogenesis induction. (B2) Final aspect of a somatic embryo cultured for one month on medium without activated charcoal (−AC).