All complete flowers contain four whorls: the calyx, corolla, androecium, and gynoecium. The pollen contains two cells— a generative cell and a tube cell—and is covered by two layers called the intine and the exine.

The female gametophyte is formed from mitotic divisions of the megaspore, forming an eight-nuclei ovule sac. The stamens are made up of anthers, in which pollen grains are produced, and a supportive strand called the filament.

stamens — made up of anthers, in which pollen grains are produced, and a supportive strand called the filament. female gametophyte — formed from mitotic divisions of the megaspore, forming an eight-nuclei ovule sac. gametophyte — multicellular stage of the plant that gives rise to haploid gametes or spores. micropyle — opening on the ovule sac through which the pollen tube can gain entry.