Table 1. Definitions.

Term	Definition
Apomixis	Plant asexual reproduction through seed. Progeny of an apomictic plant are genetically identical to the maternal plant.
Embryo sac	Multicellular female gamete-producing structure of a flowering plant. Also known as the female gametophyte.
Apomeiosis	Avoidance or failure of meiosis during the development of an embryo sac.
Diplospory	Apomeiosis pathway where a diploid embryo sac develops from the megaspore mother cell.
Apospory	Apomeiosis pathway where a diploid embryo sac develops from a somatic ovule cell that is not the megaspore mother cell, called the aposporous initial (AI) cell.
Parthenogenesis	Development of an egg found in a diplosporous or aposporous embryo sac into an embryo without fertilization.