Apoximis is an interesting phenomenon in which the genetic identity of the mother plant is transmitted to daughter plants that develop by seed formation and germination. Apoximis is a form of asexual propagation because there is no union of male and female gametes before seedling production. There are several types but a common one is that found in citrus seeds where, in addition to the sexual embryo formed through the usual pollination and fertilization processes, embryos also arise in the nucellar tissue (nucellar budding). The nucellar tissue enclosing the embryo sac has not undergone reduction division and has the same genetic makeup as the female parent. So the nucellar embryos, although developing in a seed, are exactly the same genetically as the mother plant and thus maintain the clone.
Such seeds on contain several nucellar embryos in addition to the sexual embryo. Thus, several seedlings are obtained from one seed, a situation known as polyembryony.
Even though plants arising by apoximis from nucellar embryos maintain the clone, they go through the juvenile to mature transition stages just as any woody plant seedling would, taking a number of years to flower and fruit.
J.mcmahon, Margaret, et.al,. 2002. Hartman’s plant science. New Jersey: Pearson Eduction.